[求助]og11 sc 62题

62. 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.

(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

the key is D,but I choose B.答案的解释是：Since the dumping continues into the present, the past perfect verb had been allowed should instead be the present are allowed.为什么be allowed的动作会一直持续到现在，何以见得？我的理解是be allowed动作在reduce之前，即在协议要求减少phosphates数量之前，居民还是可以将其到入湖中，要求减少数量后，居民就不能往湖里倒。如果按解释所说居民到目前还可以往湖里倒phosphates，那协议又是怎么减少phosphates的？谢谢

减少不等于禁止吧

另外，如果用过去完成时，在agreement的时候都已经倒进去了，怎么减少呢？

是从过去的某时刻开始，一直到现在都有效的agreement，这个agreement使得排放量限制，所以这里指的是现在的允许排放量。

时态是由句子含义决定的吧

另外，我在做大全SC987的时候第2题就是这道题，答案解释中A和D都有：

2, sec14-19

A is best. 1972应用reduced, 故C, E错。B, C的the phosphate amount错，B的had been dumping句意不对。

E的
                allowed for错，by municipalities改变句意。D的are allowed时态错。the amount应该是指reduced前的量, 故应过去的过去had been allowed。

OG-11^th的答案是D

An agreement that occurred in 1972 is correctly described with the past tens verb reduced.Since the dumping continues into the present, the past perfect verb had been allowed should instead be the present are allowed.

A Had been allowed should be are allowed.

B The phosphbates amount should be the amount of phosphates;the meaning of the sentence is changed by the omission of any form of allow.

C The present tense reduces should be the past tense reduced;the phosphate amount should be the amount of phosphates;have been allowed should be are allowed

D Correct.The past tense reduced is correctly used in this sentence to describe a past action,and the present tense are allowed is used to describle the present situation.

E The present tense reduces should be the past tense redueced;allowed for dumping is an incorrect idiom;allowed for dumping by municipalities is awkward

 不过应该以OG为准吧