AttherequestofsomeEnglishlearners,hehaspublishedalotofb...

问题详情：

At the request of some English learners, he has published a lot of books, one of _______ is about English idioms.

   A. whom                        B. those                        C. them                        D. which

【回答】

D

知识点：定语从句

题型：选择题