________ caused the accident is still a complete mystery.
A．WhatB．That C．HowD．Where
A
解析　主語從句中缺少主語，而能在主語從句中既充當主語又起引導(dǎo)作用的只有what。
練習冊系列答案
相關(guān)習題

科目：高中英語 來源：不詳 題型：單選題

It is by no means clear ________ the president can do to end the strike.(2012·新課標全國，24)
A．howB．which
C．thatD．what

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

I usually do my homework after dinner until 10 pm, ______ is my bedtime.
A．whoB．whatC．whichD．that

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

The average rainfall in Ningxia is small, _____ makes the climate here is drier ______
with other cities in China.
A．that; comparedB．which; comparingC．which; comparedD．that; comparing

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

The Foreign Minister said，“________ our hope that the two sides will work
towards peace.”
A．This isB．There is
C．That isD．It is

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

________ the meeting himself gave them a great deal of encouragement.
A．The president will attendB．The president to attend
C．That the president attendedD．The president attending

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

It remains unknown ________ the peace talk between the two countries is going to lead.
A．where B．when
C．howD．why

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

Did it ever occur to you　　　you would give up the plan to go abroad?
A．that B．whyC．ifD．whether

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

In my opinion _________ matters is whether we can win together as a team instead of individuals.
A．howB．itC．thatD．what

查看答案和解析>>

同步練習冊答案