单选题 "A, better, richer and happier life for all our citizens." That's the American (41) . In practice, it means living in a spacious, air-conditioned house, owning a car or three and maybe a boat or a holiday home, not to mention flying off to (42) destinations.
The trouble (43) this lifestyle is that it consumes a lot of power. If everyone in the world started living like wealthy Americans, we (44) need to generate more than 10 times 45 energy each year. And (46) , in a century or three, we all expect to be (47) by an army of robots and fly into space on holidays, we are going to need a vast amount more. Where are we going to get so much power from?
It is clear that continuing to rely on (48) fuels will have catastrophic results, because of the dramatic warming effect of carbon dioxide. But alternative power sources will affect the climate too. For now, the climatic effects of "clean energy" sources are trivial (49) those from greenhouse gases, but if we keep on using ever more power over the coming centuries, they will become ever more (50).

单选题 A. constitution B. dream C. history D. character

单选题 A. exotic B. patriotic C. supersonic D. alcoholic

单选题 A. on B. for C. at D. with

单选题 A. shall B. will C. should D. would

单选题 A. much more B. more than C. as much D. of more

单选题 A. if B. though C. while D. so

单选题 A. taken to B. attended to C. attached to D. submitted to

单选题 A. rock B. stone C. fossil D. diamond

单选题 A. according to B. based on C. such as D. compared with

单选题 A. significant B. imperative C. indispensable D. negligible