— Each of the students, working hard at their lessons, the book. — So have I.
A. is reading
B. has read
C. reading
D. reads
网友回答
A. is reading
(答案→)B. has read
C. reading
D. reads
解析：此题将主谓一致和时态结合在一起进行考查。上一句的主语为each of the students 是单数，再结合下文的回答so have I，由此，可知上句应该用完成时态。