20.-Must I turn off the gas after taking a bath?

　 --Of course. You can never be _______ careful with that.

A.enough　　　　　　　　　 B. too　　　　　　　 　C. so　　　　　　　 　　D. very

19.When spelling a long word, be careful not to ________ a single word.

A. leave out　　　　　　　 B. leave for　　　　　 　C.leave off　 　　　　　D. leave alone

18.The teacher was _______ when he heard the _______ news.

A. annoying;annoying　 　　　　　　　　　　　　　B. annoying;annoyed　

C. annoyed;annoyed　　 　　　　　　　　　　　　D. annoyed;annoying

17.The mother didn't know who _______ for the broken glass.

A. blamed　　　　　　　　 B. to blame　　　　 　　C. should blame　　　 　D. would blame

16.Washington, a state in the United States,was named ________ one of the greatest American

presidents, _________ him.

A. after;in honour of　　　　　　　　　　　　　　 B. for;in favor of

　 C. after;in praise of　 　　　　　　　　　　　　　　D. for;in place of