请教：大全2

everhappyin

1.        A 1972 agreement between Canada and the United States
                        reduced the amount of phosphates that municipalities had been allowed to dump into the Great Lakes.

(A) reduced the amount of phosphates that municipalities had been allowed to dump

(B) reduced the phosphate amount that municipalities had been dumping

(C) reduces the phosphate amount municipalities have been allowed to dump

(D) reduced the amount of phosphates that municipalities are allowed to dump

(E) reduces the amount of phosphates allowed for dumping by municipalities

答案是a

不明白，完全不懂

谢谢：）

everhappyin

难道大全上的答案是错的？？

大全是在D后面写的（A）

答案是以后面写的为准，还是以在哪里写的为准？

everhappyin

谢谢gonghao

everhappyin

OG11还有哪些答案是改过的呢？