What is most likely to be discussed in the paragreh that follows?A.Steps to improving water use managet.B.Ways tor redjuce the costs of builing dams.C.Measured to dmal with worldwide water shortages.D.Appmihes to handling the pressure on water supply.
What is most likely to be discussed in the paragreh that follows?
A.Steps to improving water use managet.
B.Ways tor redjuce the costs of builing dams.
C.Measured to dmal with worldwide water shortages.
D.Appmihes to handling the pressure on water supply.
相关考题：
What keeps Grimsvotn still?A. The slow flow of waterB. The low water temperatureC. The thick glacierD. The water pressure
EThe need to feed a growing population is putting much pressure on the world’s supply of water. With 97% of the world’s water too salty to be drunk or used in agriculture, the worldwide supply of water needs careful management, especially in agriculture. Although the idea of a water shortage（短缺）seems strange to someone fortunate enough to live in a high rainfull country, many of the world’s agricultural industries experience constant water shortages.Although dams can be built to store water for agricultural use in dry areas and dry seaons, the costs of water redistribution(重新分配)are very high. Notonly is there the cost of the engineering itself, but there is also an environmental cost to be considered. Where valleys(山谷)are flooded to create dams, houses are lost and wildlife homes destroyed. Besides, water many flow easily through pipes to fields,but it cannot be transported from one side of the world to the other. Each country must therefore rely on the management of its own water to supply its farming requirements.This is particularly troubling ro countries with agricultural industries in areas dependent on irrigation（灌溉）. In Texas, farmers’ overuse of irrigation water be resulted in a 25% redcution of the water stores. In the Central Valley area of south eastern USA, a huge water engineering project provided water for farming in dry vallege, but much of the water use has been poorly managed.Saudi Arabia’s attempts to grow wheat in desert areas have been the pumping of huge quantities of irrigation water from underground reserves. Because there is no rainfall in these areas, such reserves can only decrease, and it is believed that fifty years of pumping will see them run dry.72. From the first two paragraphs we learnt that _______.A.much of the world’s water is available for useB.people in high rainfll countries feel luckyC.the costs of water redistribution should be consideredD.water can be easily carried through pipes across the world
Which of the following is true?A.The water in Texas have been reduced by 75%.B.Most industries in the world suffer from water shortagers.C.The underground water in Saudi Arabia might run out in 50 years.D.Good management of water use resulted from the project in the Central Valley.
The text is mainly about .A.water supply and increasing populationB.water use management and agricultureC.water redistribution and wildlife protectionD.water shornages and environmental protection.
29． The writer thinks that people in large cities should __________ ．A． stop the used water from getting into undergroundB． only use the water from the riversC． make their used water clean againD． use as much sea water as possible
The main propulsion diesel engine jacket water temperature rises above normal, with the raw sea suction and the expansion tank water level being normal. Which of the following problems is most likely the cause?A.Faulty thermostatic bypass valveB.Eroded zinc pencils in the heat exchangerC.Steam formation in the expansion tankD.Excessive leakage from jacket water pump seals
What is the most usual reason for the fresh water-sea water heat exchanger fouling in the sea side?A.lube oil sludge accumulating in itB.dirt and scale etc , formed on the surfacesC.deformation of the tubes and the shell or the platesD.lube oil leakage into sea-water side
what chemicals did you use to treat the boiler water ?when you test alkalinity and acidity of water in boiler by pH test paper ? the result shows the boiler water is in acidiity . please describe what the possible cause is .
The most common type of containment device for spilled oil on the water is the use of _____.A.strawB.boomsC.skimmersD.chemical dispersants
What alarm is NOT found on an inert gas system ________．A.Low oxygen alarmB.Low pressure alarmC.Scrubber high water level alarmD.Deck seal low water alarm
The water we drink and use is running short in the world.We all have to learn how to stop wasting our limited water.One of the steps we should take is to find ways of reusing it.Experiments have already been done in this field.Today in most large cities,fresh water is used only once,then it runs into waste system.But it is possible to pipe the used water to a purifying factory.There it can be filtered and treated with chemicals so that it can be used again,just as it were fresh from a spring.But even if every large city purified and reused its water,we still would not have enough.Then we could turn to the oceans.All we’d have to do to make use of the seawater on earth is to get rid of the salt.This process is called desalinization,and it is already in use in many parts of the world.The way to stop wasting our limited water is to________.A.do experiments with waterB.purify the used water and reuse itC.use fresh water once againD.make use of seawater
Farmers use water in many ways.（） they use water to grow crops.AIn factBFor exampleCBesidesDBecause of this
Farmers use water in many ways.（） they use water to grow crops.A、In factB、For exampleC、BesidesD、Because of this
单选题Supposing there is a water container. The taller the container, ______ at the bottom.Agreater will the water pressure beBthe water pressure will be greaterCthe greater the water pressure will beDgreater the water pressure will be
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Supposing there is a water container. The taller the container, _____at the bottom.Agreater will the water pressure beBthe water pressure will be greaterCthe greater will be the water pressureDgreater the water pressure will be
单选题We use （） to distill fresh water from sea water.AengineBsea water pumpCcylinder coolerDfresh water generator
单选题The three conditions which cause engine shutdown are overspeed，low lube oil pressure，and（）.AHigh lube oil pressureBHigh jacket water pressureCHigh jacket water temperatureDLow jacket water pressure
单选题What alarm is NOT found on an inert gas system? （）ALow oxygen alarmBLow pressure alarmCScrubber high water level alarmDDeck seal low water alarm
单选题The most common type of containment device for spilled oil on the water is the use of （）.AstrawBboomsCskimmersDchemical dispersants
单选题Farmers use water in many ways.（） they use water to grow crops.AIn factBFor exampleCBesidesDBecause of this
单选题In a diesel engine jacket water cooler, with seawater cooling the fresh water, the（）Asea water temperature must never be warmer than 40℃Bjacket water pressure should always be greater than the sea water pressureCjacket water temperature must always be less than 60℃Djacket water pressure must always be less than the sea water pressure
单选题The second stage feed-water temperature and shell absolute pressure in a multistage, flash type, distilling plant is （）Ahigher than the first stage feed-water temperature and absolute shell pressureBlower than the first stage feed-water temperature and absolute shell pressureCthe same as the first stage feed-water temperature and absolute shell pressureDnot related to the feed-water temperature and absolute shell pressure
单选题In a closed cooling water system, which of the problems can cause the water pressure to fluctuate?（）AAn open vent in the cooling systemBA fouled sea chestCA restricted water passage in the engineDAir entrained in the cooling water
单选题The main propulsion diesel engine jacket water temperature rises above normal, with the raw water sea suction and the expansion tank water level being normalWhich of the following problems is most likely the cause?（）AFaulty thermostatic bypass valveBEroded zinc pencils in the heat exchangerCSteam formation in the expansion tankDExcessive leakage from jacket water pump seal
单选题During loading and discharging operations，in addition to when the cargo tanks have been properly filled，each inert gas system must be capable of maintaining a minimum gas pressure of（）.A150 millimeters of water pressureB125 millimeters of water pressureC100 millimeters of water pressureD75 millimeters of water pressure
单选题The boiler feed pump discharge pressure is higher than the steam drum pressure to （）.Aensure feed water flow into the boilerBkeep the steam drum pressure highCprevent water hammer in the feed lineDhelp the feed water flash to steam