30. In a formal interview,you should always try to maintain good eye contact with the interviewers.

31. Once you have had the disease,you are immune to it for the rest of your life,which means that you cannot get it again.

32. Though he worked very hard,it took him a long time to acquire the skills he needed to become a professional artist.

33. The spread of international crime and corruption constitutes (建立）a major threat to the global economy.

34. Each of us might define the concept of freedom in a slightly different way.

35. It predict that 300 million people will become infected in the next ten years and,without treatment,each victim will infect 10 to 15 others every year.

36. This story,which tells about a man protecting his wife and children, illustrates how important the family is in Asian culture.

37. At the airport,people stood behind a metal fence waiting for passengers to emerge from customs.

38. When applying for a job, make sure you emphasize the skills and knowledge you have that an employer would find important to the job.

39. There is no doubt that this new type of tire represents a major advance in road safety;you feel safer when driving on the highway.