__ does he call? Once a month

__ does he call? Once a month

1. ________ does he call? Once a month.

A.How seldom   

B.How long     

C.How soon     

D.How often    

.标准答案：D

2. Looking through the window, I found him ________ in a sofa.

A.to seat      

B.seat         

C.seating      

D.seated       

.标准答案：D

3. I told your friend how to get to the hotel, but perhaps I _________ have driven her there.

A.could        

B.must         

C.ought        

D.should       

.标准答案：D

4. You should be careful when __________the street in big cities.

A.to cross     

B.cross        

C.crossing     

D.crossed      

.标准答案：C

5. An invention is usually the end result of a long ___ of ideas, expressions, and improvements.

A.selection                  

B.sequence                   

C.combination                

D.cooperation                

.标准答案：B