大全 648;補充41

                             Since chromosome damage may be caused by viral infections, medical x-rays, and exposure to sunlight, it is important that the chromosomes of a population to be tested for chemically induced damage be compared with those of a control population.fficeffice" />

(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 chemically induced damage are to be comparable with

the answer is (A), but i don't why. Where can I f find out the explain ??or who can explain it for me??

thanks

谁能帮忙翻译一下，谢谢！

不用了，看明白了，谢谢！