Tom has two cousins and are engineers.A. both of whomB. both of themC. none of themD. ei

问题补充：

Tom has two cousins, and are engineers.

A. both of whom

B. both of them

C. none of them

D. either of them

答案：

A. both of whom

(答案→)B. both of them

C. none of them

D. either of them

解析：考查句子结构；本题两部分之间有并列连词and, 说明前后都是并列的句子，没有所谓的主句和从句，排除A项。根据two，说明是两者之间，排除none，因为None是指三者或者三者以上。根据横线后面的are说明主语是复数形式，故B正确。D项做主语是单数形式。