21.The foreigner tried his best, but he still couldn't make his point ____. 　A.understand　 　B.understanding 　C.to understand 　 D.understood

20.People ____　in the city do not know the pleasure of country life. 　A.live　　 B.to live　　 C.lived　　 D.living

19.The ____　price will save you one dollar for each dozen.　　　 　A.reduce　　 B.reducing　　 C.reduced　　 D.reduces

18.The student corrected his paper carefully, ____the professor's uggestions. 　　　　　　　　　　　　　　　　　　　　 　A.follow　 B.following　 　C.followed　 D.being followed

17.He went from door to door, ____waste papers and magazines.　 　A.gathering　　B.gathered　 　C.gather　　 D.being gathered

16.　 ____the office, the foreign visitors were shown round the teaching uilding. 　　　　　　　　　　　　　　　　　　　　 　A.Having shown　 B.Showing　 　C.Has shown　 D.Having been shown

15.With winter ____on, it's time to buy warm clothes.　　　　 　A.came　　es　　e　　ing

14.Deeply ____, I thanked her again and again.　　　　　　　 　A.being moving　　 B.moved　　 C.moving　　 D.to be moved

13. ____how to do the homework, I went to ask my teacher for help. 　A.Not to know　 B.Not knowing 　C.Knowing not　 D.Not known

12.I've never heard the word ____in spoken English.　　　　 　A.use　　 B.used　　 C.using　　 D.useing