PREP 一题

痴迟

In some species of cricket, the number of chirps per minute used by the male for attracting females rise and fall in accordance with the surrounding temperature, and they can in fact serve as an

approximate thermometer.

(A) for attracting females rise and fall in accordance with the surrounding temperature, and they can

in fact serve

(B) for attracting females rises and falls in accordance with the surrounding temperature, which can

in fact serve

(C) in attracting females rise and fall in accordance with the surrounding temperature, in fact

possibly serving

(D) to attract females rises and falls in accordance with the surrounding temperature, and it can in

fact serve

(E) to attract females rises and falls in accordance with the surrounding temperature, in fact

possibly serving

答案是D，但我很疑惑D中的it指代的是谁？前面的crips是复数啊，难道指的是temperature或number?意思不通啊！！！