You’d better look up the new word in a dictionary you don’t know it.A. ifB. asC. thoughD.

问题补充：

You’d better look up the new word in a dictionary you don’t know it.

A. if

B. as

C. though

D. whether

答案：

(答案→)A. if

B. as

C. though

D. whether

解析：句意：如果你不知道这个新单词，最好去查字典。A 如果；B 正如；C 尽管；D 是否；结合题意故选A。