求助： OG-SC-#74

running2k

74： 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
Answer: D.

But i don't understand why A is wrong. why "had been " can't be used here. Had been means it happens before the agreement, and "the amount of p had been allowed before the agreement was reduced by 1972 agreement ...."

thank you...

sayysong

个人意见
如果是had been allowed的话，那么就是协议签订前的垃圾倾倒量，已经发生了的事情，靠协议没法再挽回了。
题目想说的是1972年(过去的时间点)签订的协议减少了(从那以后的)垃圾倾倒量。
也就是说到目前为止还在遵守这个约定。

cx_ding

我这样理解，请楼主和牛牛们指证：
过去完成时表达发生在过去的过去，并且在过去某一点已经结束。
从逻辑含义上说，这个文件签署以后，才减少了垃圾倾倒。
垃圾倾倒没有在过去的时间点结束，而是延续至今。

running2k

我觉得过去完成时其实还表示过去的过去发生的这个动作对现在（一般过去式的动词）的影响。
而且， of p, and that m... had been allowed.. 都是修饰amount的，并不是指 had been dumped， 是指在agreement之前的法律允许的。所以还是不明白为什么不能用had been allowed.请nn们指点。

yhwut

OG解释里的意思是dump是现在也在发生的客观事实，不能用过去时

running2k

yhwut, 可是，过去完成时修饰的不是dump, 是修饰的allowed...

singletonboy

这题其实有问题，出题者的意思是现在这个污染物还在被排放，所以后面用了一般现在时
我觉得理会GMAC的意思就可以了， 也就是说根据具体意思判断合适时态（其实这一点很难把握，有时候有被GMAC刷着玩的感觉）

hnqxsky

首先排除CE后 A B D 里最大的区别就是 allowed 的时态了
一个是过去完成时 一个是一般现在时
如果是过去完成时的话  是减少的以前被允许倒的P（had been 最起码表示在 1972 agreement 之前） 这显然不符合逻辑
所以不能用had been allowed