Question

It worries the couple a lot ______ their only son is behaving worse and worse these days.

A．how

B．why

C．that

D．what

Answer 1

C

试题分析：考查主语从句，这里it是形式主语，that是引导主语从句，主语从句中不缺成分，用that引导，句意：他们唯一的儿子最近表现越来越差让这对夫妇很担心。选C。
点评：引导主语从句的that在从句中不做成分，只起到连接的作用，学生要会分析句子成分。