17. Recently，extensive studies (statistics/surveys/investigations/...) show (reveal/indicate/demonstrate/prove/...) that 07 Chinese cities and 23 small towns suffer water shortages.
18. These days we often tell that...， but is this really the case?
19. There are three major values of owning a car (a computer/an apartment/a mobile phone/a beeper/...). To begin with .... Next .... Last .... There are， on the other hand， more reasons against it. First (ly)... Second (ly) .... Finally .....
20. There are some reasons for owing a car ( traffic accidents/big fires in big cities/water shortages/destruction of virgin forests/... ).
21. In the past several years there has been...
22. Now an increasing number of people come to realize that time is money ( knowledge is power/science and technology energize economic growth/we must learn to live in harmony with wildlife/weak nation has no international prestige/cheating never pays/science and technology constitute the primary productive force/... ).
23. There are three basic differences between the large and small universities (cities and countryside/ceramics and plastics materials/... ). In the small university， you... In the large university， you...
24. There are various ways (at least three ways/possible techniques/problems/methods/approaches/... ) to do something.
25. Now it is commonly held that... but I doubt whether...
26. The policy ( The president/The major/The reform/The bidding for the 2008 Olympic Summer Games) enjoys grass-root support for three main reasons，
27. Smoking (alcoholic beverage/Drugs/Guns/Firecrackers/... ) should be banned from college campuses for two reasons. The first reason is that... The other reason is that... (on the one hand .... On the other hand .... )
28. There is a general discussion today about the issue of...
29. No pains， no gains. No money， no honey (friendship/work/promotion/admission/love/assistance/service/justice/... ). No
shirt ( shoes ) ， no admission.
30. We enjoy Internet surfing not because we are curious about new things， but because Internet represents the latest technology.
31. The possible solutions of the energy crisis (water shortages/desertification/pollution/theses social problems/... ) depends on....