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.
额 987第2题 答案怎么和OG上的不一样 OG上选D 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
那能不能拜托你解释下“It just mentions the one event. We don't have a second event or activity that occurs after... so we can't use past perfect. ” 为什么reduce和 dumping不能是两件事,而后面他新用的句子里的fine和dumping就可以是两件事呢?