A number of books in the library been stolen so that the number of them smaller than befo

问题补充：

A number of books in the library been stolen so that the number of them smaller than before.

A. have, is

B. has, is

C. has, are

D. have, are

答案：

(答案→)A. have, is

B. has, is

C. has, are

D. have, are

解析：考查单复数，主语是A number of books，是复数形式，所以是have，the number of表示…的数量，是单数，所以是is，所以选A