so作连词时，无法和and连用；thus非连词

and so 各自单独使用
and thus连用

这个句子并列的两个动词应该是comes和is studied吧？exhibited前面省略了which is，作为定语。

D是一主两谓

and thus 是 ok 的
so 做所以(conj.)用时，不能与and连

错选 E and so 都是连词 只能用一个...

A选项：只有连词能连接两个句子，副词thus无法连接句子，因此，本选项的exhibit句和is studied句之间缺少连词。
PS：连词分为并列连词和从属连词，thus, then, therefore 等词，并不是连词，而是副词！

thus是副词而不是连词所以不能连接句子,,, 前句的谓语是comes 之前读的时候没有注意到，如果用个从句把comes的谓语地位改变，直接上a选项才是合理的

说逗号abce都错了那个 突然觉得很有道理啊。

ABCE的逗号都错了吧？如果加逗号，也应该是在引号外面。

b里的is best 是一个系表结构
d best做副词修饰studied
e it is best ,it 是个形式主语，这样主语都变了，也就不对了

• [no object] (of an artist) display one's work to the public in an art gallery or museum: she was invited to exhibit at several French museums.
2. manifest or deliberately display (a quality or a type of behavior): he could exhibit a saintlike submissiveness.
patients with alcoholic liver disease exhibit many biochemical abnormalities.

exhibit verb
[with object]
1. publicly display (a work of art or item of interest) in an art gallery or museum or at a trade fair: only one sculpture was exhibited in the artist's lifetime.

exhibit 是及物动词还是不及物动词？我这里不太明白。字典显示的是都可以。如果是及物动词，表示被动的话，那么整个句子是可以做主语的The type of behavior exhibited when an animal recognizes itself in a mirror comes within the domain of "theory of mind,"答案是不是A就是对的。

and so这个用法在字典可以查到。。。 so是可以做adv的。而且gmat有题目的正确答案中用到了and so。 所以E不能直接根据and so去判断错误吧。。。
求老师解答

老师，请问 is best to be studied 和 is best studied 在这题中有没有考点呢？两个有什么区别？

OG2017V-SC-296求大神指教