21. （ ） A. private B. special C. traditional D. expensive

22. （ ） A. run B. walk C. live D. surf

23. （ ） A. funny B. low C. beautiful D. dangerous

24. （ ） A. through B. by C. around D. for

25. （ ） A. after B. since C. or D. while

26. （ ） A. whether B. although C. if D. before

27. （ ） A. space B. air C. room D. ship

28. （ ） A. quickly B. nearly C. normally D. quietly

29. （ ） A. divides B. protects C. locks D. mentions

30. （ ） A. wash away B. warm up C. cool off D. clean out

31. What should you do if you have a headache? In modern times people often take aspirin (阿司匹林). But is aspirin 31. ________ (actual) a modern medicine?

32. More than 4,000 years ago, ancient Egyptians used dried leaves to treat pain. And in the fourth century B.C., a medicine made from tree bark (树皮) 32. ________ (use) to treat fevers.

33. In the nineteenth century, European scientists discovered that both medicines have the same chemical (化学物质). They used the chemical to make a modern medicine—aspirin. Today, it’s one of the world’s 33. ________ (cheap) and most helpful medicines.

34. Some of the medicines we have today come 34. ________ traditional Chinese medicine.

35. In the third century B.C., some people 35. ________ (begin) studying the human body.

36. They tried many different ways to treat the patients and recorded 36. ________ (they) results.

37. For more than 2,000 years, doctors recorded 37. ________ they found in books.

38. These ancient books are still useful today. Tu Youyou, a Chinese medical researcher, found that in 38. ________ past, people used a herb with yellow flowers to treat fevers.

39. For 39. ________ (century), Western medicine paid little attention to traditional Chinese medicine.

40. But today, scientists are studying traditional treatments 40. ________ (develop) new medicines.