问题
选择题
Maria has written two novels, both of ________ have been made into television series.
A．them
B．that
C．which
D．what
答案
答案：C
考查非限制性定语从句的用法。此处先行词是two novels，后面是一个非限制性定语从句且介词前置，因此用both of which引导。句意：Maria写了两部小说，两部都被拍成了电视剧。