OG 12 SC 74老题新问，关于present perfect。求NN现身！！！

zzrrqq0708

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
答案是选D。我知道C不对，reduces的时态不对，并且phosphate amount的说法也不对。
我的问题是：C中的现在完成时是否是对的呢？Mahatten里面总结的现在完成时态的用法有两种，一个是动作持续到现在，另一个是动作的影响持续至今。那么在这道题中，agreement的影响是不是算持续至今呢？那么如果用现在完成时态是不是也可以呢？
求NN解答！！！多谢多谢！

zzrrqq0708

自己顶！！！求NN现身！！！

zhouyanpu

我也想知道！

jetyxo

同问，帮顶！为什么可以用are allow 和 were allowed，不能用 have allowed呢？？？

wellsli

根据manhattan的深层次理解，这句话分两部分，第一部分：agreement 去 reduced，没有异议吧。第二部分：municipalities are allowed to dump。 manhattan 说：
Do not une the perfect tense when the simple tense will do. The GMAT prefer simplicy.

Wrong: Joe learned about an epoch in which dinosaurs had walked the earth.
Right: Joe learned about an epoch in which dinosaurs walked the earth.

in the first example, the past perfect had walked is unecessary. Although the action had walked does take earlier than the action learned, th eariler action does not bearing on the context of the later action. The sequence of time does not need to be clarified or emphasized. Thus, the past perfect is considered wrong in this context.

You should use the pefect tense only when you can justify them with the rules described in these sections. if an action begin in the past and continue to the present (or its effect does), use the present perfect tense. If one action in the past precedes another, and you need to clarify or emphasize the time sequence, then use the past pefect. Otherwise, stick to the simple tenses.

这一题，我发现，确实虽然第一部分很可能发生在第二部分之后（先允许倾倒再减少），但是是“agreement”去reduce，而allowed 是市政府 被allowed， 两部分没有意思上很密切的关联，没有去clarify和emphasis它们之间先后顺序的必要，因此！不用had been 也不用have been。 再者OG喜欢简单，喜欢一般时态，所以用are allowed。

看了别人manhattan的分析才这样想的~

Elroy

思路：
A：订立【法规条文】，所修改的东西一定是【从订立起始点，以后生效的东西】所以had beend 是个错误时态； 1972年的法律不能减少市民在那之前 被允许倾倒的垃圾的量 ；也就是说法规的内容的时态 或者和订立是相同，或者比订立时晚

B：phosphate amount是个很挫的表达方式，一般改成amount of phosphates；had been as in A;
随意删掉了A中的实意动词allow，改变了句意，不是减少市民倾倒的垃圾，而是减少允许他们倾倒的垃圾；

C：reduces 不能修饰1972年得agreement,改为reduced ; have been allowed改为are allowed ；phosphate amount是个很挫的表达方式，一般改成amount of phosphates；

D：正确；that 的补出，结构清晰

E：reduces 不能修饰1972年得agreement,改为reduced ; allowed for dumping  错误， be allowed to do ； 原句说municipalities had been市民被允许去倾倒，这里allowed for dumping by municipalities  被市民允许去倾倒的

总结：
保留介词结构(除非介词是of有时允许变化)，一些结构，最好不要省略介词结构==>location, places, time, period, quantity or other measurements (也不要用物主格来描述这些词:比如The bee's population…. Orz)