Question

The first thing           we should do is to tell him the news.

A． who

B．which

C．that

D．whom

Answer 1

C

解析试题分析：句意：我们应该做的第一件事情就是要告诉他这个消息。定语从句的先行词受到序数词的修饰时，关系代词只能用that来引导；故选C。
考点：考查定语从句。