Children’s brains can’t develop properly_______ they lack protein.
A．whenB．sinceC．becauseD．unless
A
本題考查when的一個特殊用法。在本題中的when引導的是一個條件狀語從句，相當于if。整個句子的意思是：如果孩子缺少蛋白質，大腦就不能正常發(fā)育。
練習冊系列答案
相關習題

科目：高中英語 來源：不詳 題型：單選題

All the dishes in this menu， _____ otherwise stated， will serve two to three people.
A．asB．ifC．thoughD．unless

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

It took seven years __________ they finally got married.
A．sinceB．afterC．beforeD．when

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

He was told that it would be at least three months ___ he could recover and return to work.
A．whenB．beforeC．sinceD．that

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

My parents were quarrelling about me ____ I could not quite tell why．
A．sinceB．thoughC．ifD．until

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

With the development of science,a computer is to a manager_______a gun is to a soldier.
A．asB．whatC．thatD．when

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

______ you understand the rule, you can do it well.
A．ForB．AsC．OnceD．While

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

    everybody enjoys fresh cut flowers around his house．few people know how to keep them for as long as possible．
A．BecauseB．SinceC．WhileD．If

查看答案和解析>>

科目：高中英語 來源：不詳 題型：單選題

How can they learn anything ______ they spend all their spare time watching television?
A．beforeB．whenC．althoughD．as

查看答案和解析>>

同步練習冊答案