20. This printer is of good quality. If it _______ break down within the first year, we would repair it at our expense.

A. would　　 　　　　　　 B. should　　 　　　　　　　 C. could　　 　　　　　　 D. might

19. The teacher asked us to write a ________ article.

A. 700 word　　　　　 B. 700-words　　　　 C. 700’s words　　　　 D. 700-word

18. I used to be a very delighted girl. I guess no human being could have passed _______ childhood.

　 　 A. a happy　　 　　　　　 B. a happier　　 　　　　　 C. the happier　　 　　　 D. the happiest