－Are these library books?－Yes .A. it isB. they areC. this isD. these are

问题补充：

－Are these library books?

－Yes, .

A. it is

B. they are

C. this is

D. these are

答案：

A. it is

(答案→)B. they are

C. this is

D. these are

解析：句意：—这些是图书馆的书吗？—是的，它们是。当上句的主语是these时，答语不能用these来回答，而用对应的复数代词they。本题考查交际用语中的习惯用法，故选B.