--Why are the windows so dirty?
--Because we_________them for a long time.
A. have cleaned          B. haven't cleaned       C. didn't clean
B
句意：窗戶為什么這么臟？——因為我們有很久不打掃他們了。結(jié)合語境可知下文描述的是從過去一直持續(xù)到現(xiàn)在的動作，否定語氣，故用現(xiàn)在完成時態(tài)否定形式，選B。
練習冊系列答案
相關(guān)習題

科目：初中英語 來源：不詳 題型：單選題

Jack ______ allowed to go to the movies with me yesterday evening．
A．a(chǎn)reB．isC．wereD．was

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

Mr. Wu___this math problem____him many times, but he still doesn’t understand it.
A．explains ; toB．has explained ; forC．has explained ; toD．explained ; with

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

This is the best hour I can _________ I_________ in the past twelve years.
A．know;have had　B．remember;had
C．think of;have had　D．think out;had

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

Alice interviewed some people and asked them about ____ on Father' s Day .
A. what they do             B. what they did.   C. what they will do .

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

When Jim’s mother came in, he _______ his homework.
A．is doing    B．has done   C．was doing

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

Is Tom at home?
No, he_______ to town.
A．has beenB．has goneC．goesD．will go

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

The sports meeting           next month .
A. will  hold       B. is going to hold .         C. will be held .

查看答案和解析>>

科目：初中英語 來源：不詳 題型：單選題

—Where is Sally?
—Oh, she      in the art room.
A．drawsB．drewC．is drawing D．can draw

查看答案和解析>>

同步練習冊答案