Stephen Hawking believes that the earth is unlikely to be the only planet ______

题型：不详难度：来源：

Stephen Hawking believes that the earth is unlikely to be the only planet _______ life has developed gradually.

A．that

B．where

C．which

D．whose

答案

B

解析

试题分析：考查定语从句：先行词是the only planet，定语从句缺少地点状语，用where引导定语从句，句意：Stephen Hawking认为地球不可能是生命逐渐发展的唯一星球。选B.
点评：定语从句的考查主要就是考查关系词的辨析，关系代词that, which, whose, whom, as， who在句中做主语，宾语，表语或者定语；where, why, when在句中做状语。要分析句子成分，看缺少什么成分，就选用相应的关系词。