单选题 The medicine has many functions, ______ are unknown to us.
  • A. some of which
  • C. that some of them
  • B. of which some of them
  • D. which of them
【正确答案】 A
【答案解析】逗号后面是非限定性定语从句，由which引导，which指代functions，同时作从句的主语，此处which前有限定词some of。句意：这个药有许多作用，其中有一些是不为我们所知的。