语法大全285 (讨论区中没有) 请教

285.     Even though the state has spent ten years and seven million dollars planning a reservoir along the Ubi
                River, the project will have to be abandoned as a result of the river becoming so heavily polluted.

(A) will have to be abandoned as a result of the river becoming so heavily polluted

(B) is to be abandoned on account of the heavy pollution which the river received

(C) had to be abandoned because the river had received such heavy pollution

(D) has to be abandoned because of the river and its heavy pollution

(E) must be abandoned because the river has become so heavily polluted (E)

BCD错，但是A为何错呢？must指主观必须，而这里project要被abandoned是客观要求。

A,

1.最好用一般现在时，will不太好，但不是致命的错误；

2.as a result of the river(becoming...)，没有表示出具体的原因，因为这样就使表达的重点转移到了river上，而实际应该是在heavily polluted上（abandon的原因是污染，不是河本身）；

3.表示原因不用as a result of，说什么已经有了结果，描述这个结果由什么造成的时候用as a result of，本题只是陈述一个情况，没有说已经be abandaned，而且本题的语态用because更好；