四、閱讀測驗       Ocean waves represent our planet’s last untapped large-scale renewable energy resource. Over 70 %of the earth’s surface is covered with water. The energy contained within waves has the potential to produceup to 80,000 TWh (1012 watt-hours) of electricity per year—sufficient to meet our global energy demandfive times over.       No wonder the idea of extracting energy from ocean waves and turning it into electricity is an alluringone. The first serious attempt to do so dates back to 1974, when Stephen Salter of Edinburgh Universitycame up with the idea of “ducks”: house-sized buoys tethered to the sea floor that would convert the swellinto rotational motion to drive generators. It failed, as have many subsequent efforts to perform the trick.But the idea of wave power will not go away, and the latest attempt—the brainchild of researchers at OscillaPower, a firm based in Seattle—is trying to address head-on the reason why previous efforts havefoundered.       This reason, according to Rahul Shendure, the firm’s boss, is that those efforts took technologiesdeveloped for landlubbers (often as components of wind turbines) and tried to modify them for marine use.The consequence was kit too complicated and sensitive for the rough-and-tumble of life on the oceanwaves, and also too vulnerable to corrosion. Better, he reckons, to start from scratch.       Instead of generators with lots of moving parts, Oscilla is developing ones that barely move at all.These employ a little-explored phenomenon called magnetostriction, in which ferromagnetic materials(things like iron, which can be magnetized strongly) change their shape slightly in the presence of amagnetic field. Like many physical processes, this also works in reverse. Apply stresses or strains to sucha material and its magnetic characteristics alter. Do this in the presence of permanent magnets and a coilof wire, such as are found in conventional generators, and it will generate electricity.
【題組】36. What are NOT true about ocean waves?
(A) They can be turned into electricity.
(B) Stephen Salter successfully used “ducks” to convert them into electricity.
(C) There have been attempts to convert them into electricity.
(D) Oscilla Power is one of the firms to convert them into electricity.