OG12 74 用语义也不能理解

水一下。 这题自己也看过几遍了。很能够理解lz的想法啊！！说得不好见谅啊~
XDF 讲义说。“政府法令 具有持续性 应该是得用 一般时态的”

OG解释说，had been allowed 这个时态 说明 过去一段时间 允许 倾倒 磷肥, 现在已经不允许了。
但是，因为倾倒磷肥 这个动作 在协议（agreement）之后任然继续，所以用一般现在时。
og 中解释第二句，Since the dumping continued after the date of the agreement, the past perfect verb HAD BEEN ALLOWED should instead be the present ARE ALLOWED .........

ps: that 似乎应该修饰 phosphates 吧？ that 应该紧跟先行词。

白勇的语法全解上面 答案还是 错误的A 和lz选的一样！
白勇是这么写的
第一步：时间标志 1972 决定了谓语动词reduce 必须使用一般过去时态。排除C、E
“D选项 定语从句的一般现在时 are allowed to ... 与主句的一般过去时态 reduced sth., 时态不协调。 排除 D  这个 说错啦！！
第二步：定语从句就近修饰名词 amount, Municipalities had/have been dumping amount to the Great Lakes. 动作 dump 和动作对象 amount, 逻辑搭配不合理。 排除 B、C。

白勇的答案 和 OG 上的不一致。 应该还是以OG 为准的吧！

og解释： Since the dumping continued after the date of the agreement, the past perfect verb bad been allowed should instead be the present are allowed (if the agreement remained in effect when the sentence was written) or the past were allowed (if the agreement was no longer in effect when the sentence was written).

我的理解：定语从句修饰的是pho。。 不是amount of P。即定语从句意思是：被允许倒的P，而非lz所说：之前被允许倒的量。
所以agreement之后还在倒，不能用完成时。

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~

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)