Since chromosonme damage may be caused by viral infections, medical x-rays, and exposure to sunlihgt, i is important that the chromosomes of a population to be tested for chemically induced damage be compared with those of a control population.
A) to be tested for chemically induced damage be compared with
b) being tested for damage induced chemically are compared with
c)being tested for chemically induced damage should be compared to
d) being tested for chemically induced damage are to be compared to
e) that is to be tested for chemicalinduced damage are to be comparable with
答案是A。 b, c, and d肯定不对,但E错在那里?那位指点一下。
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