请问OG-184及并列句中的逗号问题

泰格尔

184. As measured by the Commerce Department, corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher costs.

(A)  and have slipped since then, as many companies have been unable to pass on higher costs

(B)  and have slipped since then, the reason being because many companies have been unable to pass on higher costs

(C)  and slipped since then, many companies being unable to pass on higher costs

(D)  but, many companies unable to pass on higher costs, they have slipped since then

(E)  yet are slipping since then, because many companies were unable to pass on higher costs

OG在其解释中多次提到：对于并列从句，连词后的分句应该都算是一个重新独立的句子，故应该用逗号隔开。但为何选项A的and之前无逗号呢？

联系到OG-207的正确答案：In the textbook publishing business, the second quarter is historically weak, because revenues are low and marketing expenses are high as companies prepare for the coming school year.

此题中and前后连接两个并列分句，且主语不同，为何在and之前没有ETS所认为该有的逗号呢？

OG218的正确答案也与上述问题相同：

State  health officials have ordered that the levels of bacteria in seawater at popular beaches be measured and the results published.

此题中and之前无逗号；且从并列角度来看，虽然results之后省略了be，但and之后的that能省略吗？

能否请NN们告之其中奥妙？谢谢！

我笨，我努力

我做了很多题了，是第一次看到，and的前面必须用逗号的说，你可以再翻翻og的解释吗？贴上来看看呀

and 是个并列连词，你只要注意它的前后句子是否并列对称就可以了，你举的三个例子都很好，都是很好的并列的例子

184. As measured by the Commerce Department, corporate profits peaked in the fourth quarter of 1988 and have slipped since then, as many companies have been unable to pass on higher costs.

and 链接前后发生的两个动作

联系到OG-207的正确答案：In the textbook publishing business, the second quarter is historically weak, because revenues are low and marketing expenses are high as companies prepare for the coming school year.

and 链接的两个句子表述的公司经营中的两种状态，性质相同且表述方式对称

State  health officials have ordered that the levels of bacteria in seawater at popular beaches be measured and the results published

我想如果有加上that的选项当然是最优的，这样使句子结构清楚了很多，其实og很对题是要求象order，require的从句后带上that的，但最优的没有的情况下，退而求其次，这个答案也不算错呀。可能这个题还是重点在考你对对称的把握吧。

只有最好没有更好－－－og的风格

泰格尔

谢谢你的解释！

对于OG要求并列句and前用逗号的表述，请见OG-135

135. Intar, the oldest Hispanic theater company in New York, has moved away from the Spanish classics and now it draws on the works both of contemporary Hispanic authors who live abroad and of those in the United States.

(A)  now it draws on the works both of contemporary Hispanic authors who live abroad and of

(B)  now draws on the works of contemporary Hispanic authors, both those who live abroad and those who live

(C)  it draws on the works of contemporary Hispanic authors now, both those living abroad and who live

(D)  draws now on the works both of contemporary Hispanic authors living abroad and who are

(E)   draws on the works now of both contemporary Hispanic authors living abroad and those

In choices A and C, it intrudes between the halves of the compound verb has moved... and [now] draws to introduce a new grammatical subject, thereby creating a run-on sentence:the inclusion of it requires a comma after classics to set off the new independent clause

结合上述OG的解释，不知如何看待我前面所提的“并列句中的逗号”问题？

谢谢！

我笨，我努力

不好意思很久没有上来啦

我还是很仔细看了，大全解释，看了很多遍，嘻嘻，也是很晕呀

我想它的意思是这样的：

在A和C的选项中，在两个动词中间插入了一个it，新的一个主语，这样就造成又出现了一个意思连贯的独立的句子，所以需要加上逗号隔开。

它这么要求是因为加上逗号后句子的结构更加清晰吧，我实在找不到其他解释了。这一题关键是两：

1.it的用法，独立出现要留意判断，一般都是指代主语，出现两个名词要审用。同一主语要省略，使句子简练

2.both －－－and 结构出现一定要完整