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

问题补充：

A series 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：

A. have, is

(答案→)B. has, is

C. has, are

D. have, are

解析：考查主谓一致。本题第一空的主语是A series of books谓语动词与series保持一致，使用单数形式；the number of…指“…的数量”做主语时，谓语动词用单数的形式。句意：图书馆里一系列的书都被偷掉了，以至于这些书的数量比以前也少了很多。故B正确。