Question

Having lost his key，________.

A．he couldn’t enter the room	B．the gatekeeper offered to help
C．the door was forced open	D．the room couldn’t be entered

Answer 1

A

试题分析：考查句子结构：逗号前面是现在分词的完成式做状语，说明句子的主语应该是lost his keys的逻辑主语，应该是he，句意：丢了钥匙后，他不能进入房间。选A。
点评：用非谓语动词做状语，说明主从句的主语一致的时候，做题时可以在四个选项中找非谓语动词的逻辑主语，往往逻辑主语对了，答案就自然出现了。