Tom has two cousins, and are engineers.
A. both of whom
B. both of them
C. none of them
D. either of them
网友回答
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。