Question

Having checked the doors were closed and ______ all the lights were off, the boy opened the door to his bedroom.

A．why

B．that

C．when

D．where

Answer 1

B

试题分析：句意：已经检查完门是关着的，所有的灯都灭了，这个男孩打开了他的卧室的门。这里逗号后是一个句子，逗号前是非谓语动词的形式，and连接的是Having checked的两个宾语，宾语从句不缺成分故用that，故选B。
点评：本题难度适中。这里考查的宾语从句的连词，that在宾语从句中不做成分，一般可省略，但是当有两个从句并列时，后面的从句的连词that不能省略。
即学即练：Did he point out ______ you were wrong?
A. why     B. that      C. when      D. where
解析：D。句意：他有没有指出你什么地方错了？