CR9.8 Sunflowers growing in pots were placed, with their roots submerged, in the pond contaminated with radioactive elements. The sunflowers kept growing; in the process, they absorbed radioactive elements. Within twelve days, 85 percent of the radioactive elements were removed from the water, which is no less than can be accomplished with the much more expensive conventional filtration techniques. Scientists therefore propose using sunflowers for decontamination wherever there are radioactively contaminated ponds.

Which of the following, if true, points to a limitation on the applicability of the proposed method of decontamination?

A. Some plants other than sunflowers can also remove radioactive elements from water.

B. The water in many ponds contaminated with radioactive elements is so cold that it would kill

sunflowers whose roots were submerged in it.

C. Sunflowers that grow with their roots submerged in water grow less well than sunflowers

growing under optimal conditions on dry land.

D. Only species of sunflowers with large leaves can have their roots submerged in water and still

keep growing.

E. In ponds in which the circulation of the water is artificially increased, sunflowers absorb

radioactive elements far faster than they do in other ponds.

我选择了B,但正确答案是C.我认为B选项削弱了该计划实施的可能性。答案C我认为是一个无关选项，S在土地上生长情况与题目无关。

我的解答：