GWD-18-Q29怎么没人讨论过？快考了，诚心请教

The contractor and the engineer agree on the cause of the bridge failure, but both blame the other.

A B

A.    both blame the other

B.    each blames the other

C.    each blame the other person

D.    both are blaming the other

E.     each blames one another

为什么答案是B啊？

我认为but后省略的主语同前半句，即The contractor and the engineer，所以谓语肯定是blame，而不可能是blames啊。

另外，prep1中有道题，解释中说each和the other的搭配是错的。如下：

It seems likely that a number of astronomical phenomena, such as the formation of planetary nebulas, may be caused by the interaction where two stars orbit each other at close range.

(A) may be caused by the interaction where two stars orbit each other

(B) may be caused by the interaction between two stars that each orbit the other

(C) are because of the interaction between two stars that orbit each other

(D) are caused by the interaction of two stars where each is orbiting the other

(E) are caused by the interaction of two stars orbiting each other

答案是E

It seems likely that a number of astronomical phenomena, such as the formation of planetary nebulas, may be caused by the interaction where two stars orbit each other at close range.

题目要表达的意思是:那一堆天文现象,例如PN的形成,是由于在同一轨道上的两颗星星互相吸引.

我认为这道题目的重点在于如何修饰interaction.

(A) may be caused by the interaction where two stars orbit each other (where用法不对; two stars orbit each other我认为没有错)

(B) may be caused by the interaction between two stars that each orbit the other (orbit应该用单数;不过就算用了单数都不如E简洁)

(C) are because of the interaction between two stars that orbit each other (because of 用法不对)

(D) are caused by the interaction of two stars where each is orbiting the other (where用法不对;进行时也不对)

(E) are caused by the interaction of two stars orbiting each other (简洁,清晰; orbiting分词短语修饰two stars比B答案的定从更加简洁)

我觉得GMAT语法里最最王道的是句子的意思，在这题里不能去管each other什么的。如果是both blame the other，就可能理解成两者都一起指责没有出现的第三方，引起歧义。如果用both也要说both blame each other。因此答案中只有B意思表达清楚且时态正确。

轨道那道，E和D相比就是简洁，应该和each other无关的

个人浅见：

第一道题必须是each，原因就像楼上说的，这类题在og上都太多了，可以说是gmac的偏好，先说大家都怎样，all呀both呀，然后笔锋一转，再说一下每一个怎么着。。。这里both是不可容忍的，直译就是两人怎样怎样，但是他们都批评别人。楼主感觉出问题所在了吧，其实就是楼上的意思。

第二道题，还是题意理解问题，咱们到底想怎么修饰interaction，究竟是俩星星就相交了呢，还是俩星星相互绕才能相交？一个是名词修饰，一个是事件修饰，显然前者是有逻辑错误的，所以d项根本是万劫不复，都不用去管搭配错误。其他选项就是三楼那么解释的。

这里我还有一个存疑：a，b项的may be是否与句首的likely语义重复呢？留待大牛解决。。。

谢谢各位的耐心指教。

原来觉得SC的正确率还可以，稳定在80%以上。这两天做prep，感觉就不太好了，有点慌啊……prep确实有些题比较灵活。

我认为zliycwn1说得有道理，很多以前认为王道的判断方式不一定奏效，最主要的还是逻辑意思，both用在这里确实会有歧义。

还有china101说的a,b项may be和likely是有语义重复的，prep语法笔记中也是这么说的。

谢谢指教！

thx