With the prospect of coal and petroleum supplies running out and with air pollution becoming an increasing concern, the major countries of the world are seeking alternate sources of energy. If a means to obtain energy from water, especially from the ocean, can be effected economically, it would provide a never ending supply of energy, since 70% of the earth’s surface is ocean and another 10% is fresh water in rivers and lakes.From the beginning of time man has used waterpower as a source of working energy---waterfalls and dams---but these are fresh water sources and are landlocked. The seas have contributed little or nothing in the way of power. The use of temperature variation between currents is one area of exploration. Ocean water is heated by the sun near the equator and drawn by the rotation of the earth toward the poles, where it cools and drops toward the ocean floor and starts its journey back toward the equator. The differential between the two currents is 1 °C and 7°C. To use it, the scientists must find the places where they run near land and are not too far away from each other.America, the greatest consumer of energy, has been working on another kind of thermal sea energy proposal. One plan would somewhat resemble the operation of a refrigerator on a vast scale. Warm water would be the heat source, cold water the heat sink. A component such as fog would be liquid at a cold temperature and turn to gas as it warmed.Oceans also offer wave power, tides and the chemical reaction of salt water as potential sources of energy. All these uses are theoretically possible. Britain is interested in wave power, using a string of “tear drop” devices that depend on very active wave areas at 100 feet depths. In addition to this, the British are working on a method that the Japanese have already put into practical use on a small scale for powering their navigational boats. This method is called an oscillating （振荡的）water column and rides the waves with a series of cylinders（气缸）having one-way air valves. Wave movement produces air under pressure that has only one escape route——to a turbine（涡轮机）that powers a generator.1.The use of water referred in this passage is（ ）.2.In the matter of developing energy from ocean water, Britain is（ ）.

3.The development of oceanic water power is important because（ ）.4.Getting energy from the ocean is important to（ ）.5.The oscillating water column produces power from（ ）.

A.a new concept compared with other ways of natural resources B.less expensive than petroleum and other means of energies C.now being used more from the ocean than from rivers and lakes D.being developed to supplement other sources of energy问题2： A.working on an old Japanese method B.the most advanced country in the field C.following the lead of the United States D.consolidating their work with operations问题3： A.there will be a shortage of coal and petroleum B.it is the cheapest method of producing energy C.petroleum supplies are being steadily drained D.obtaining energy from ocean water is simpler问题4： A.Russia because of its limited coal and petroleum resources on land B.America because it is the greatest consumer of energy in the world C.Asia because most of Asian countries lack other sources of energy D.South America because a great part of its population is very poor问题5： A.the turbine that powers the generator B.the generator that produces electricity C.the cylinders that drives the turbine D.the air that escapes to the turbine