Question

It has been proved eating vegetables in childhood helps to protect you against serious illnesses in later life.

A. if B. because

C. when D. that

Answer 1

D

【解析】

试题分析：考查主语从句和形式主语。此句中，it为句子的形式主语，而proved后面的从句才是该句的真正主语，即为主语从句。该主语从句中，eating vegetables in childhood helps to protect you against serious illness in later life 并不缺少任何成分，所以只需用that引导即可。if/because都不能用于引导主语从句，排除AB，when表示从句缺少时间状语也不对。句意：童年吃蔬菜有助于晚年健康的观点已经被证实。故选 D。

考点：考查主语从句和形式主语