问答题You are trying to fill a bath with both taps on, but have accidentally left out the plug. Normally the hot water tap takes 8 minutes to fill the bath and the cold water tap takes 10 minutes. However, the water empties out through the plug hole in 5 minutes. How long will it take for the bath to fill?
问答题
You are trying to fill a bath with both taps on, but have accidentally left out the plug. Normally the hot water tap takes 8 minutes to fill the bath and the cold water tap takes 10 minutes. However, the water empties out through the plug hole in 5 minutes. How long will it take for the bath to fill?
参考解析
解析：
设浴缸容量为x，n为三管一起开的充满水的时间，热水充满浴缸要8分钟，所以每分钟充满x/8，同理冷水每分钟充满x/10，而放水管每分钟放水x/5，故可列方程(x/8+x/10－x/5)×n=x，解得n=40，即需40分钟。
设浴缸容量为x，n为三管一起开的充满水的时间，热水充满浴缸要8分钟，所以每分钟充满x/8，同理冷水每分钟充满x/10，而放水管每分钟放水x/5，故可列方程(x/8+x/10－x/5)×n=x，解得n=40，即需40分钟。
相关考题：
A） 信息归纳（共5小题，每小题1分）阅读下面短文，完成信息卡：Skin-diving is a new sport today. This sport takes you into a wonderful new world. It is like a visit to the moon. When you are under water, it is easy for you to climb big rocks, because you are no longer heavy.Here, under water, everything is blue and green. During the day, there is plenty of light. When fish swim nearby, you can catch them with your hands.When you have tanks of air on your back, you can stay in deep water for a long time. But you must be careful when you dive in deep water.To catch fish is one of the most interesting parts of this sport. Besides, there are more uses for skin-diving. You can clean ships without taking them out of water. You can get many things from the deep sea.Now you see that skin-diving is both useful and interesting.In formation CardA new sport today81.___________
Passage FourArchimedes was a famous Greek mathematician and scientist. He was born around 287 BC and he died in the year 212 BC.Archimedes is most well-known for one specific idea that he came up with. "Archimedes's Principle" states that a solid object which is immersed in a liquid is pushed up by a force which is equal to the weight of the water that the object moves. For example, if you put a piece of wood and a piece of gold the same size in water, only the wood will float. Both the wood and gold move the same amount of water, but the wood weighs less than this water, while the gold weighs more.It is believed that Archimedes discovered this principle when the king of Syracuse asked him to solve a problem. The king wanted to know if his crown was pure gold or a mixture of gold and silver. The king, of course, did not melt his crown to find out. The idea came to Archimedes as he lowered himself into his bath. He noticed how the water spilled out of the tub. He decided to use the same idea for the crown. He knew that a gold crown immersed in water would weigh more than one made of silver. The experiment was done and the goldsmith was proved guilty of trying to cheat the king.48. A good title for the selection is______.A. ArchimedesB. Archimedes's PrincipleC. A Gold and Silver CrownD. The King of Syracuse
Once a week my aunt would announce, "I am going to have my bath today."Now most people find it fairly simple to have a bath.You probably remember how it goes.You enter the bathroom, you put the plug in, turn on the hot water, get into the bath, wash, sing, get out, dry yourself and exit.My aunt's approach was more epic(宏大的), like one of those long Eisenstein films where people seem to be climbing up the same flight of stairs forever.My aunt would first slowly collect her clean linen(亚麻布衬衫), so as to have it all ready for changing into after her bath.This involved sorting out her linen, which took up most of the morning.Sometimes she would find an old letter buried among her linen, become interested in the memories it aroused and have to postpone the bath until the next day.But if all went well, she would have a bite of lunch and start Phase Two around two o'clock.Phase Two was washing out the bath.She would wash the bath very thoroughly, rinse(冲洗) it with running cold water, rewash it and then carefully feel the whole surface with her fingers.If there was the slightest blemish, she would clean the whole bath out again.This took about an hour.Then she would fill the bath.By this time she was feeling a bit hungry and exhausted.So she would put on the kettle for a cup of tea.Several cups of tea and several cream crackers (her favourite food) later, she would go back to the bathroom.And find the water stone cold.1.According to the writer, most people().A.read magazines in the bathB.make bath time a special occasionC.sing when they are in the bathD.have a bath once every other week2.The writer's aunt().A.never got used to taking a bath regularlyB.always treated bathtime as an eventC.hated climbing the stairs to the bathroomD.would collect her new linen quickly3.How did she use to spend most of the morning?()A.Reading old letters.B.Preparing lunch.C.Getting the bath water hot.D.Sorting out her linen.4.Why might the writer's aunt put off bathing until the next day?()A.She might get fascinated by an old letter.B.She would sometimes get too tired.C.She would sometimes have lunch instead.D.She might start ironing the linen.5.She would never fill the bath until she().A.had cleaned it at least three timesB.had had several cups of teaC.had polished it inside and outsideD.had made sure it was perfectly clean
When sailing ill cold zones,_______should be drained of water.A.the ventilation pipeB.the water line for fire fighting on the deckC.the fuel oil lineD.the water supplying line in bath room
Which of the following would be considered downflooding on a fishing vessel as defined in regulation?A.Vessel heels until water enters a hatchB.Vessel in collision floods through a damaged area above the waterlineC.Vessel takes on water due to the hatches being left open in heavy rainD.Vessel takes on water by the propeller shaft due to failure of the stern gland
Which statement about damage control is TRUE ________．A.A hole in the hull at the waterline is more dangerous than a hole below the inner bottomB.The amount of water entering a ship through a hole varies inversely to the area of the holeC.Water flowing into a lower compartment on a ship is more dangerous than water on deck or flowing into an upper compartmentD.Water flowing over the forecastle bulwark is more dangerous than a hole in the hull at the waterline
请阅读短文，完成此题。When we analyze the salt salinity(盐溶度 ) of ocean waters, we find that it varies only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation. In this manner, the salinity is increased, since the salt stays behind. If this is carried to the extreme, of course, white salt would be left behind; this, by the way, is how much of the table salt we use is actually obtained.The opposite of evaporation is precipitation, such as rain, by which water is added to the ocean. Here the ocean is being diluted so that the salinity is decreased. This may occur in areas ofhigh rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by-evaporation, or decreased by the addition of fresh water by precipitation.Normally, in hot regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.In the Weddell Sea, the densest water in the ocean is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portion of the oceans of the world.The purpose of mentioning the Weddell Sea is__________.查看材料A．to give an example of cold-water salinityB．to point out the location of deep watersC．to make a comparison between hot-water salinity and cold-water salinityD．to show that the water in the Weddell Sea varies in salinity from place to place
共用题干Some doctors think that you should drink a glass of water each morning. You should drink water before doing anything else.The temperature of the water should be similar to body temperature:not hot,not cold.Why should you drink this water?______(46).It helps clean out your kidneys.It prepares your stomach for digestion.______(47).After drinking water,the intestines can more easily take out nutrients from our food. And water helps us go to the bathroom more easily.Scientists suggest that people take in 1,600 milliliters of water each day.______(48).If you do,your kidneys will have to work much harder to eliminate it. It's better to drink some in morning and some in afternoon.______(49).And during meals,they think water dilutes the juices produced in our stomachs.This can interfere with normal digestion.Are you drinking enough water every day?Check the color of your urine.______(50).if your urine is very dark yellow,your probably need to drink more water. A little water each day could make you much healthier._________（47）A:If it is light yellow,you are probably drinking enoughB:Water can also help your intestines work betterC:Some people think it's better to drink between mealsD:Water helps your body in many waysE:But don't drink all of that water in one sitting F: Water is an essential element of life
The purpose of mentioning the Weddell Sea is___________.A.to give an example of cold-water salinityB.to point out the location of deep watersC.to make a comparison between hot-water salinity and cold-water salinityD.to show that the water in the Weddell Sea varies in salinity from place to place
共用题干The Drink Your Body Needs MostI Our bodies are estimated to be about 60% to 70% water. Blood is mostly water,andour muscles,lungs,and brain all contain a lot of water. Water is needed to regulate bodytemperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxygen to our cells,removes waste,and protects our joints andorgans.2 We lose water through urination（排尿）,respiration（呼吸）,and by sweating. If youare very active,you lose more water than if you do not take much exercise.Symptoms ofmild dehydration（脱水）include chronic pains in joints and muscles, lower back pain, headaches, and constipation（便秘）.A strong smell to your urine, along with a yellowcolor indicates that you are not getting enough water. Thirst is an obvious sign ofdehydration and in fact,you need water long before you feel thirsty.3 A good rule of thumb（好的做法）is to take your bod犷weight in pounds and divide thatnumber in half. That gives you the number of ounces（盎司）of water per day that youneed.For example,if you weigh 160 pounds,you should drink at least 80 ounces of waterper day.If you exercise you should drink another 8-ounce glass of water for every 20minutes you are active.If you drink coffee or alcohol,you should add at least an equalamount of water. When you are traveling on an airplane,it is good to have 8 ounces ofwater for every hour you are on board the plane.4 It may be difficult to drink enough water on a busy day.Be sure you have water handy atall times by keeping a bottle for water with you when you are working,traveling,orexercising.If you get bored with plain water,add a bit of lemon for a touch of flavor.Thereare some brands of flavored water available,but some of them have sugar or artificial sweeteners that you don't need. Paragraph 4__________A:Ounces of water needed per dayB:Importance of waterC:Composition of waterD:Signs of dehydrationE:Supply of waterF:Necessity for bringing a bottle for water with you
共用题干The Drink Your Body Needs MostI Our bodies are estimated to be about 60% to 70% water. Blood is mostly water,andour muscles,lungs,and brain all contain a lot of water. Water is needed to regulate bodytemperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxygen to our cells,removes waste,and protects our joints andorgans.2 We lose water through urination（排尿）,respiration（呼吸）,and by sweating. If youare very active,you lose more water than if you do not take much exercise.Symptoms ofmild dehydration（脱水）include chronic pains in joints and muscles, lower back pain, headaches, and constipation（便秘）.A strong smell to your urine, along with a yellowcolor indicates that you are not getting enough water. Thirst is an obvious sign ofdehydration and in fact,you need water long before you feel thirsty.3 A good rule of thumb（好的做法）is to take your bod犷weight in pounds and divide thatnumber in half. That gives you the number of ounces（盎司）of water per day that youneed.For example,if you weigh 160 pounds,you should drink at least 80 ounces of waterper day.If you exercise you should drink another 8-ounce glass of water for every 20minutes you are active.If you drink coffee or alcohol,you should add at least an equalamount of water. When you are traveling on an airplane,it is good to have 8 ounces ofwater for every hour you are on board the plane.4 It may be difficult to drink enough water on a busy day.Be sure you have water handy atall times by keeping a bottle for water with you when you are working,traveling,orexercising.If you get bored with plain water,add a bit of lemon for a touch of flavor.Thereare some brands of flavored water available,but some of them have sugar or artificial sweeteners that you don't need. Dehydration may occur if there is a shortage of water_________.A:in your bodyB:without waterC:before longD:for a changeE:on a busy dayF:to your weight
共用题干The Drink Your Body Needs Most1. Our bodies are estimated to be about 60%to 70%water. Blood is mostly water, and our mus- dles,lungs and brain all contain a lot of water. Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxy-gen to our cells,removes waste,and protects our joints and organs.2. We lose water through urination（排尿）, respiration（呼吸）, and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration （脱水）include chronic pains in joints and muscles,lower back pain,headaches,and constipation（便秘）.A strong smell to your urine,along with a yellow color indicates that you are not getting enough water. Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 .A good rule of thumb（好的做法）is to take your body weight in pounds and divide that num- her in half. That gives you the number of ounces（盎司）of water per day that you need.For ex-ample,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you ex- ercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water. When you are traveling on an airplane,it is good to have 8 ounces of water for every hour you are on board the plane.4 .It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising. If you get bored with plain water,add a bit of lemon for a touch of flavor. There are some brands of fla-vored water available,but some of them have sugar or artificial sweeteners that you don't need. The amount of water your body needs per day is related_________.A: in your bodyB: without waterC: before longD: for a changeE: on a busy dayF: to your weight
共用题干The Drink Your Body Needs Most1 Our bodies are estimated to be about 60% to 70% water.Blood is mostly water,and our muscles,lungs,and brain all contain a lot of water.Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxygen to our cells,removes waste,and protects our joints and organs.2 We lose water through urination（排尿）,respiration（呼吸）,and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration（脱水）include chronic pains in joints and muscles , lower back pain, headaches, and constipation（便秘）.A strong smell to your urine , along with a yellow color indicates that you are not getting enough water.Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 A good rule of thumb（好的做法）is to take your body weight in pounds and divide that number in half. That gives you the number of ounces（盎司）of water per day that you need.For example,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you exercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water.When you are traveling on an airpiane,it is good to have 8 ounces of water for every hour you are on board the plane.4 It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising.If you get bored with plain water,add a bit of lemon for a touch of flavor.There are some brands of flavored water available,but some of them have sugar or artificialsweeteners that you don't need. One cannot live_______.A:in your bodyB:without waterC:before longD:for a changeE:on a busy dayF:to your weight
共用题干The Drink Your Body Needs Most1. Our bodies are estimated to be about 60%to 70%water. Blood is mostly water, and our mus- dles,lungs and brain all contain a lot of water. Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxy-gen to our cells,removes waste,and protects our joints and organs.2. We lose water through urination（排尿）, respiration（呼吸）, and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration （脱水）include chronic pains in joints and muscles,lower back pain,headaches,and constipation（便秘）.A strong smell to your urine,along with a yellow color indicates that you are not getting enough water. Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 .A good rule of thumb（好的做法）is to take your body weight in pounds and divide that num- her in half. That gives you the number of ounces（盎司）of water per day that you need.For ex-ample,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you ex- ercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water. When you are traveling on an airplane,it is good to have 8 ounces of water for every hour you are on board the plane.4 .It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising. If you get bored with plain water,add a bit of lemon for a touch of flavor. There are some brands of fla-vored water available,but some of them have sugar or artificial sweeteners that you don't need. Paragraph 1________A: Ounces of water needed per dayB:.Importance of waterC: Composition of waterD: Signs of dehydrationE: Supply of waterF: Necessity for bringing a bottle for water
共用题干The Drink Your Body Needs Most1 Our bodies are estimated to be about 60% to 70% water.Blood is mostly water,and our muscles,lungs,and brain all contain a lot of water.Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxygen to our cells,removes waste,and protects our joints and organs.2 We lose water through urination（排尿）,respiration（呼吸）,and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration（脱水）include chronic pains in joints and muscles , lower back pain, headaches, and constipation（便秘）.A strong smell to your urine , along with a yellow color indicates that you are not getting enough water.Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 A good rule of thumb（好的做法）is to take your body weight in pounds and divide that number in half. That gives you the number of ounces（盎司）of water per day that you need.For example,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you exercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water.When you are traveling on an airpiane,it is good to have 8 ounces of water for every hour you are on board the plane.4 It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising.If you get bored with plain water,add a bit of lemon for a touch of flavor.There are some brands of flavored water available,but some of them have sugar or artificialsweeteners that you don't need. Paragraph 3________A:Ounces of water needed per dayB:Importance of waterC:Composition of waterD:Signs of dehydrationE:Supply of waterF:Necessity for bringing a bottle for water with you
共用题干The Drink Your Body Needs Most1. Our bodies are estimated to be about 60%to 70%water. Blood is mostly water, and our mus- dles,lungs and brain all contain a lot of water. Water is needed to regulate body temperature and to provide the means for nutrients（滋养物）to travel to all our organs. Water also transports oxy-gen to our cells,removes waste,and protects our joints and organs.2. We lose water through urination（排尿）, respiration（呼吸）, and by sweating. If you are very active,you lose more water than if you do not take much exercise.Symptoms of mild dehydration （脱水）include chronic pains in joints and muscles,lower back pain,headaches,and constipation（便秘）.A strong smell to your urine,along with a yellow color indicates that you are not getting enough water. Thirst is an obvious sign of dehydration and in fact,you need water long before you feel thirsty.3 .A good rule of thumb（好的做法）is to take your body weight in pounds and divide that num- her in half. That gives you the number of ounces（盎司）of water per day that you need.For ex-ample,if you weigh 160 pounds,you should drink at least 80 ounces of water per day.If you ex- ercise you should drink another 8-ounce glass of water for every 20 minutes you are active.If you drink coffee or alcohol,you should add at least an equal amount of water. When you are traveling on an airplane,it is good to have 8 ounces of water for every hour you are on board the plane.4 .It may be difficult to drink enough water on a busy day.Be sure you have water handy at all times by keeping a bottle for water with you when you are working,traveling,or exercising. If you get bored with plain water,add a bit of lemon for a touch of flavor. There are some brands of fla-vored water available,but some of them have sugar or artificial sweeteners that you don't need. One cannot live________.A: in your bodyB: without waterC: before longD: for a changeE: on a busy dayF: to your weight
When did you last see a polar bear?On a trip to a zoo,perhaps?If you had attended a winter activity in New York a few years ago,you would have seen a whole polar bear club.These"Polar Bears"are people who-meet frequently in winter to swim in freezing cold water.That day,the air temperature was 3oC,and the water temperature was a bit higher.The members of the Polar Bear Club at Coney Island,New York are usually about the age of 60.Members must satisfy two requirements.First,they must get along well with everyone else in the group.This is very important because there are so many different kinds of people in the club.Polar Bears must also agree to swim outdoors at least twice a month from November through February.Doctors do not agree about the medical effects of cold-water swimming.Some are worried about the dangers of a condition in which the body′s temperature drops so low that finally the heart stops.Other doctors,however,point out that there is more danger of a heart attack during summer swimming because the difference between the air temperature and water temperature is much greater in summer than in winter.The Polar Bears themselves are satisfied with the benefits（or advantages）of cold-water swimming.They say that their favorite form of exercise is very good for the circulatory system（循环系统）because it forces the blood to move fast to keep the body warm.Cold-water swimmers usually turn bright red after a few minutes in the water.A person who turns blue probably has a very poor circulatory system and should not try cold-water swimming.The main benefits（or advantages）of cold-water swimming are probably mental.The Polar Bears love to swim year-round;they find it fun and relaxing.As one 70-year-old woman says,"When I go into the water,I pour my troubles into the ocean and let them float away."The passage is mainly aboutA.a group of cold-water-swimming loversB.the Polar Bears'life in New YorkC.doctors'ideas about cold-water swimmingD.the requirements of the Polar Bear Club
When did you last see a polar bear?On a trip to a zoo,perhaps?If you had attended a winter activity in New York a few years ago,you would have seen a whole polar bear club.These"Polar Bears"are people who-meet frequently in winter to swim in freezing cold water.That day,the air temperature was 3oC,and the water temperature was a bit higher.The members of the Polar Bear Club at Coney Island,New York are usually about the age of 60.Members must satisfy two requirements.First,they must get along well with everyone else in the group.This is very important because there are so many different kinds of people in the club.Polar Bears must also agree to swim outdoors at least twice a month from November through February.Doctors do not agree about the medical effects of cold-water swimming.Some are worried about the dangers of a condition in which the body′s temperature drops so low that finally the heart stops.Other doctors,however,point out that there is more danger of a heart attack during summer swimming because the difference between the air temperature and water temperature is much greater in summer than in winter.The Polar Bears themselves are satisfied with the benefits（or advantages）of cold-water swimming.They say that their favorite form of exercise is very good for the circulatory system（循环系统）because it forces the blood to move fast to keep the body warm.Cold-water swimmers usually turn bright red after a few minutes in the water.A person who turns blue probably has a very poor circulatory system and should not try cold-water swimming.The main benefits（or advantages）of cold-water swimming are probably mental.The Polar Bears love to swim year-round;they find it fun and relaxing.As one 70-year-old woman says,"When I go into the water,I pour my troubles into the ocean and let them float away."DoctorsA.encourage people to take part in cold-water swimming activelyB.point out the possible danger of blood illness during cold-water swimmingC.believe swimming is helpful both in winter and in summerD.have different ideas about the medical effects of cold-water swimming
When did you last see a polar bear?On a trip to a zoo,perhaps?If you had attended a winter activity in New York a few years ago,you would have seen a whole polar bear club.These"Polar Bears"are people who-meet frequently in winter to swim in freezing cold water.That day,the air temperature was 3oC,and the water temperature was a bit higher.The members of the Polar Bear Club at Coney Island,New York are usually about the age of 60.Members must satisfy two requirements.First,they must get along well with everyone else in the group.This is very important because there are so many different kinds of people in the club.Polar Bears must also agree to swim outdoors at least twice a month from November through February.Doctors do not agree about the medical effects of cold-water swimming.Some are worried about the dangers of a condition in which the body′s temperature drops so low that finally the heart stops.Other doctors,however,point out that there is more danger of a heart attack during summer swimming because the difference between the air temperature and water temperature is much greater in summer than in winter.The Polar Bears themselves are satisfied with the benefits（or advantages）of cold-water swimming.They say that their favorite form of exercise is very good for the circulatory system（循环系统）because it forces the blood to move fast to keep the body warm.Cold-water swimmers usually turn bright red after a few minutes in the water.A person who turns blue probably has a very poor circulatory system and should not try cold-water swimming.The main benefits（or advantages）of cold-water swimming are probably mental.The Polar Bears love to swim year-round;they find it fun and relaxing.As one 70-year-old woman says,"When I go into the water,I pour my troubles into the ocean and let them float away."According to the passage,some doctors believe it is true thatA.you are healthy if cold-water swimming turns your skin color blueB.cold-water swimming causes more heart attacks in summer than in winterC.cold-water swimming can make the body temperature dangerously highD.Polar Bears are bears swimming in freezing water
Some villagers were going to celebrate an important wine festival（酒宴）in a few days′time,so?they borrowed a huge barrel from the nearest town,put it in the village square,and decided that each?of them should empty a bottle of the best wine he had into it,so that there should be plenty at the?feast（宴会）.One of the villagers thought he would be very clever."If I pour a bottle of water in,instead of?wine,no one will notice it,"he said to himself,"because there will be so much excellent wine in the?barrel that?the water will be lost in it."The night of the feast arrived.Everybody gathered in the village square with their bowls and?their glasses for the wine.The tap（塞子）on the barrel was opened,but what came out was pure?water.Everyone in the village had had the same idea.The underlined sentence"the water will be lost in it"can be considered as__________.A.the water would be gone in the barrelB.the water couldn't be found in the wineC.the water would flow through the barrel into the groundD.the water would be mixed up with the wine
Saw dust is used to （）.A、absorb the oilB、repair the derrickC、adjust the boomD、fill the ballast water
单选题Which would you NOT use to report the amount of anchor chain out? Three shots（）.Aat the water's edgeBon deckCon the bottomDwell in the water
单选题Which of the following would be considered downflooding on a fishing vessel as defined in regulation? （）AVessel heels until water enters a hatchBVessel in collision floods through a damaged area above the waterlineCVessel takes on water due to the hatches being left open in heavy rainDVessel takes on water by the propeller shaft due to failure of the stern gland
单选题What does the bottled water industry use in its own defense?ABottled water is much cleaner than tap water.BStudents should have freedom of choice.CThe bottles are made in a more environment-friendly way.DWater is healthier than some sodas and juices.
单选题Changing from solid to liquid, water takes in heat from all substances near it, and this _____ produces artificial cold surrounding it.AabsorptionBtransitionCconsumptionDinteraction
单选题Emma was specially trained before trying to swim the English channel, and after having a tough time with the rough and cold water, she______.Amade it Bhad succeededCgot thatDset out
问答题You are trying to fill a bath with both taps on, but have accidentally left out the plug. Normally the hot water tap takes 8 minutes to fill the bath and the cold water tap takes 10 minutes. However, the water empties out through the plug hole in 5 minutes. How long will it take for the bath to fill?