A crater lake is at the tip of a ______.A. mountainB. ridgeC. islandD. volcano
A crater lake is at the tip of a ______.
A. mountain
B. ridge
C. island
D. volcano
相关考题：
60. Tip 3 and Tip 4 give you some advice on what you should do whenyou are ______.A. inside a building B. outside a buildingC. in your house D. in a store
The ring gesture, where you form. an "O" by holding the tip of your forefinger to the tip of your thumb, means in France that you think something is(). A、worthlessB、"I'll kill you!"C、goodD、great
The villagers were surprised to see the( )of an aeroplane near the lake. A. remainsB. remainC. thingD. matter
The forest fire caused by the volcano is difficult to be______.A. put offB. put onC. put outD. put up
Passage ThreeA group of scientists rowing toward the center of a lake saw something shocking. They turned back as fast as they could. What had they seen.? The lake was boiling!The group was investigating a crater lake in the mountains of St. Vincent. A crater lake is the mouth of a volcano that has been dormant for some time and has filled with water.This particular crater was the tip of a volcano called Soufriere, which erupted last in 1902. Since that time, it had not shown any signs of action. But in the fall of 1971, mountain climbers who had hiked near the lake returned to the lowlands with strange stories. They said the water had turned yellow and was giving off a smell like burnt eggs. A seething fog was rising from the lake's surface.Local scientists rushed to Soufriere to see if this might be the beginning of a new volcanic explosion. They found a huge black mass in the middle of the water. It was a great blob 1,000 feet long and 300 feet wide. Lava had pushed up through the bottom of the lake and formed a new island.The investigators wanted to make sure that the volcano was safe, and that the lava would not over- flow into the surrounding countryside. But they could never reach the island to study it, because the lava was so hot that the water around it bubbled and boiled.44. This passage is about ______.A. mountain climbingB. a boiling lakeC. a new volcanic islandD. a mysterious blob
We can conclude that ______.A. the situation was nothing to be concerned aboutB. Soufriere is still an active volcanoC. crater lakes are easy to hike toD. Soufriere is a dead volcano
Passage FiveThe Northern Pike is a very bad fish. It is a big, hungry fish, and swallows little fish such as trout and perch. Many Northern Pikes live in Lake Davis. They are killing all the smaller fish in the lake. The Northern Pike are a serious threat to the lake because they eat all the smaller fish. Soon, all other species of fish in the lake will be killed off. This is not healthy for the environment.Experts are afraid that the Northern Pike will swim out of Lake Davis through many smaller rivers that feed into the lake. They could spread all over the country and damage many other water environments. If that happens, it would be too late to stop the Northern Pike.For ten years, officials have been trying to remove the Northern Pike from Lake Davis. They haw. tried using nets, explosives and poisons. However, the Northern Pike population is still doing well in Lake Davis. Many people do not like the idea of using poison to kill the fish. They worry that the poi- sons are bad for humans who use the water. No trace of the poisons has ever been found in local wells, however.Scientists are going to try the poison again. This time, they will drain the lake before they add the poison to the water. A public hearing will be held to talk about the problem.52. Why are some people against the use of poisons to kill Northern Pike?A. Fishermen will be poisoned too.B. The poisons are expensive.C. They think that wells will be polluted.D. The lake will become unsafe.
Which of the followings are located in Sichuan Province?A. Emei MountainB. Leshan BuddhaC. Dazu Stone CarvingsD. Fengjie County
The largest lake in Britain is _____. A.the Lough NeageB.Windermere WaterC.Coniston WaterD.the Lake District
The ring gesture, where you form. an “O” by holding the tip of your forefinger to the tip of your thumb, means in France that you think something is _______. A.goodB.greatC.worthlessD.expensive
共用题干The Exploding Lakes of CameroonWhat comes to mind when you think of a lake?You probably imagine a pretty scene with blue water, birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them, lakes may mean terrible disasters.In 1984,poisonous gases exploded out of Lake Monoun and came down into the nearby villages,killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.Lake Nyos and Lake Monoun are crater（火山口）lakes.They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottom than other crater lakes.In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster.Now scientists from the United States,France,and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.Near the top of the pipe,the team put several holes that could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level,computers will set off loud sirens（警 报）and bright lights to warn the people in the villages.In that way,they will have time to escape from the dangerous gases.Which of the following statements about Lake Nyos and Lake Monoun is true?A:They were formed in 1984.B:They are at the top of two active volcanoes.C:They are not like most other crater lakes.D:Water in them turns over regularly.
共用题干第三篇The Exploding Lakes of CameroonWhat comes to mind when you think of a lake?You probably imagine a pretty scene with blue water,birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them,lakes may mean terrible disasters.In 1984, poisonous gases exploded out of Lake Monoun and came down into the nearby villages, killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.Lake Nyos and Lake Monoun are crater（火山口）lakes. They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However,poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake. In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottomthan other crater lakes.In fact,scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster. Now scientists from the United States,France,andCameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.Theystood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air. Near the top of the pipe,the team put several holesthat could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level, computers will set off loud sirens（警报）and bright lights to warn the people in the villages. That way,they will have time to escape from the dangerous gases.A team of scientists hasA:erected a pressure-releasing pipe in the lake.B:identified the gases at the bottom of the lake.C:built a beautiful fountain near the lakes.D:removed all dangerous gases from the lakes.
共用题干The Exploding Lakes of CameroonWhat comes to mind when you think of a lake?You probably imagine a pretty scene with blue water, birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them, lakes may mean terrible disasters.In 1984,poisonous gases exploded out of Lake Monoun and came down into the nearby villages,killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.Lake Nyos and Lake Monoun are crater（火山口）lakes.They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottom than other crater lakes.In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster.Now scientists from the United States,France,and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.Near the top of the pipe,the team put several holes that could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level,computers will set off loud sirens（警 报）and bright lights to warn the people in the villages.In that way,they will have time to escape from the dangerous gases.What do we learn from the last paragraph?A:Scientists are planning to install pipes in all crater lakes.B:Scientists still do not know how to prevent gas explosions.C:Explosion disasters could be avoided in the future.D:Warning systems have been set up in the villages nearby.
共用题干The Exploding Lakes of CameroonWhat comes to mind when you think of a lake?You probably imagine a pretty scene with blue water, birds,and fish.For the people in the northwestern Cameroon,however,the image is very different.For them, lakes may mean terrible disasters.In 1984,poisonous gases exploded out of Lake Monoun and came down into the nearby villages,killing thirty-seven people.Two years later,Lake Nyos erupted.A cloud of gases rolled down the hills and into the valleys and killed 1,700 people.Lake Nyos and Lake Monoun are crater（火山口）lakes.They were formed when water collected in the craters of old volcanoes.The volcanoes under Lake Nyos and Lake Monoun are not active anymore.However, poisonous gases from the center of the earth continue to flow up through cracks in the bottom of the lake.This is normal in a crater lake.In most crater lakes,these gases are released often because the water"turns over" regularly.That is,the water from the bottom of the lake rises and mixes with the water at the top,allowing the gases to escape slowly.However,in Lakes Nyos and Monoun,there is no regular turning over.No one knows the reason for this fact,but as a result,these lakes have more gases trapped at the bottom than other crater lakes.In fact, scientists who have studied Lakes Nyos and Monoun have found 16,000 times more gases.When a strong wind,cool weather,a storm,or a landslide（滑坡）causes the water to turn over suddenly,the gases escape in a violent explosion.In the past,no one knew when the gases might explode,so there was no way for the villagers to escape disaster.Now scientists from the United States,France,and Cameroon have found a way to reduce the gas pressure at the bottom of Lake Nyos.They stood a 672-foot plastic pipe in the middle of the lake,with one end of the pipe near the bottom and the other end in the air.Near the top of the pipe,the team put several holes that could be opened or closed by a computer.Now,when the gas pressure gets too high,the holes are opened and some of the gas-filled water shoots up through the pipe into the air like a fountain.With less pressure,a disastrous explosion is much less likely.However,the scientists are not sure that one pipe will be enough to prevent explosions.They hope to put in others soon and they plan to install a similar pipe and a computer system at Lake Monoun as well.To protect people nearby until all of the pipes are in place,the scientists have installed early warning systems at both lakes.If the gas pressure rises to a dangerous level,computers will set off loud sirens（警 报）and bright lights to warn the people in the villages.In that way,they will have time to escape from the dangerous gases.A team of scientists has______.A:erected a pressure-releasing pipe in the lakeB:identified the gases at the bottom of the lakeC:built a beautiful fountain near the lakesD:removed all dangerous gases from the lakes
Before 1950 the Weather Bureau had no special system for naming hurricanes.A:storm B:blizzardC:snow D:volcano
The largest lake in Britain is( ). A.the Lake Neagh B.Windermere Water C.Coniston Water D.the Lake District
单选题What is the purpose of the passage?ATo tell people not to do dangerous sports.BTo explain what volcano surfing and land diving are.CTo talk about the world’s best volcano surfer and land diver.DTo compare activities in Vanuatu with sports in New Zealand.
单选题When did scientists fly there to watch?ABefore the volcano broke out.BAs soon as the volcano broke out.CAbout four days after the volcano broke out.
问答题Scientists hope that a remote lake on a dormant Chilean volcano can provide clues to what life may have been like in a far more distant place—the planet Mars.A 10-member team placed special plates in the lake on Licancabur volcano, at an altitude of 20,000 feet，on Sunday to measure the effects of ultraviolet light on organisms living there.The scientists, mostly from the United States, think learning how Licancabur organisms protect themselves may help researchers understand how life survived on early Earth and perhaps on early Mars as well.The damaging effects of UV radiation intensify at altitude and the air is very thin. And the lake is covered with ice most of the year, as would have been bodies of water on Mars.“If there was life on Mars 3.5 billion years ago, it could have used defense mechanisms similar to those used by the organisms at Licancabur volcano to survive,” said team leader Nathalie Cabrol.
单选题The Niagara Falls is located on the US and Canadian boundary between Lake _____ and Lake _____.ASuperior; HuronBMichigan; HuronCHuron; ErieDErie; Ontario
问答题Practice 3Maya: Away from Crowds Central America is home to many secret treasures for tourists who like to avoid the crowds, including numerous ancient Maya settlements. The seven countries of Central America—Guatemala, Panama, Belize, Honduras, El Salvador, Nicaragua and Costa Rica—are full of natural beauty and cultural treasures. Many of the region’s nature reserves, ancient Maya settlements and colonial cities have been declared world cultural heritage sites by the United Nations Educational, Scientific and Cultural Organization. There are lots of volcanoes and an exotic animal kingdom to explore, yet few people outside the region know of them. The view into the crater of the Masaya Volcano in Nicaragua is a breathtaking experience, enlivened by the accompanying strong smell of sulphur and the loud screaming of parrots. Yet the car park on the edge of the crater is nearly empty. This is a boon for daring travelers who can enjoy all the beauty without having to share it with hordes of others visitors. El Salvador has a “road of flowers” and Nicaragua has a “road of white villages” connecting villages from the colonial period. Honduras is developing a means of connecting the native American communities in the Atlantic coast from the Garifuna, descendents of the Carribean Indians and Africans, to the Miskito Indians in the jungle. Geological enthusiasts could also follow a volcanic trail through Central America. There are many volcanoes in just a small area, some with perfectly cone-shaped peaks constantly emitting smoke from their craters. Some of them are partially accessible. A bus travels to the edge of the Masaya craters in Nicaragua, an active volcano just 500 meters high. For safety reasons, every traveler should get local information from the local tourism authority before climbing a volcano. The Arenal Volcano in northern Costa Rica terrified local inhabitants and tourists in August 2000 when it spouted hot gas and ash. Individual travelers can easily find travel information. The long distance buses that connect all the countries in the region are very comfortable with air conditioning and TV. And if you travel through the villages in small, local rundown buses, you will swiftly come into close contact with local inhabitants and their animals. You are just as likely to have a hen thrust into your lap as a small child.