标题: . GWD-11-28 ;GWD-12-Q2 请指教！ [打印本页] 作者: breakable 时间: 2010-10-5 12:22 标题: . GWD-11-28 ;GWD-12-Q2 请指教！ In an effort to reduce the number of fires started by cigarettes, a major tobacco company is test-marketing a cigarette in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing the rate at which it burns and lowering the heat it generates.
A.in which thin layers of extra paper are used to decrease the amount of oxygen entering the cigarette, thereby slowing
B.in which they use thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows
C.that uses thin layers of extra paper to decrease the amount of oxygen when it enters the cigarette, thereby slowing
D.for which thin layers of extra paper are used to decrease the amount of oxygen that enters the cigarette, and thereby slowing
E.using thin layers of extra paper in decreasing the amount of oxygen entering the cigarette, which slows
Scientists are discussing ways to remove excess carbon dioxide from the atmosphere by increasing the amount that is absorbed by plant life.One plan to accomplish this is to establish giant floating seaweed farms in the oceans.When the seaweed plants die, they will be disposed of by being burned for fuel.
Which of the following, if true, would indicate the most serious weakness in the plan above?
A.Some areas of ocean in the Southern Hemisphere do not contain sufficient nutrients to support large seaweed farms.
B.When a seaweed plant is burned, it releases an amount of carbon dioxide comparable to the amount it has absorbed in its lifetime.
C.Even if seaweed farms prove effective, some people will be reluctant to switch to this new fuel.
D.Each year about seven billion tons of carbon dioxide are released into the atmosphere but only about five billion tons are absorbed by plant life.
E.Seaweed farms would make more money by farming seaweed to sell as nutritional supplements than by farming seaweed to sell as fuel.