Question

---- What has made him look like lacking sleep?
----- _____ his wife is ill and he has to get up several times a night to attend to her.

A．For

B．Because

C．That

D．What

Answer 1

C

試題分析：考察主語從句。本題指的that引導(dǎo)主語從句That his wife is ill and he has to get up several times a night to attend to her.在句中不充當(dāng)任何成分，只起引導(dǎo)和連接作用。AB不能引導(dǎo)主語從句，what要在句中作主語，賓語或者表語。句意：—什么事情讓他看起來如此缺少睡眠？—他的妻子生病了，他不得不起床好幾次來照顧她。故C正確。
點評：主語從句是在復(fù)合句中充當(dāng)主語的從句，通常放在主句謂語動詞之前或由形式主語it代替，而本身放在句子末尾。解答這類題目，關(guān)鍵在于分析清楚句子結(jié)構(gòu)。通過判斷引導(dǎo)詞在從句中所作的成分及意義，來選擇正確的引導(dǎo)詞。連接主語從句的從屬連詞主要有that, if, whether，和疑問詞（what how where when ...)。that引導(dǎo)表示陳述句的主語從句，if和whether，whether...or not引導(dǎo)表示“是否”，引導(dǎo)一般疑問句。連接代詞主要有who,whom,whose,what,whoever,whomever,whosever,whatever,whichever等。連接代詞一般指疑問，但what, whatever除了指疑問外，也可以指陳述。連接副詞主要有when, where, why, how, whenever, wherever, however等.