I was given three books on cooking, the first I really enjoyed.
A. of that
B. of which
C. that
D. which
网友回答
A. of that
(答案→)B. of which
C. that
D. which
解析：the first of which相当于and the first of the three books，即指这三本书中的第一本。又如：I met the fruit-pickers, several of whom ever university students. 我碰到那些摘水果的人，其中有好几个是大学生。