21、Apples are usually sold by _____ weight and eggs are sometimes sold by ____ dozen.

　A. the; the　　　　 B. /;a   　　C. /; the　　　 D. the; a

19、He got ____ (临时的) work while he was waiting to go to the university .

二、选择题

（每空？ 分，共？ 分）

18、It is our duty to __________(保卫) our motherland.

17、He ________(未能) to pass the driving test last summer.

16、 He will come here next ________(星期三).

15、Talking of his father’s death, she kept on ___________(擦拭) her eyes with a handkerchief.

14、A great celebration was held on his _________(50岁) birthday.  

13、The doctor told me to have more ____________（蔬菜）and fruit.    

12、Don’t be frightened by the television camera. Just speak _____(自然地).