Question

【题目】The argument is extremely heated ______ there are necessary conditions of existence such as water on the Mars.

A. that B. whether C. if D. which

Answer 1

【答案】B

【解析】

试题分析：句意：关于火星上是否有生命存在的必需条件这一争论极其激烈。A. that 引导名词性从句，不做成分只起连接作用。B. whether引导名词性从句，“是否” C. if引导宾语从句，“是否” D. which引导定语从句，做主语或宾语；从句是解释争论的内容，引导同位语从句，故选B。