In recent years, especially during the 1960s, there was much discussion about "the brain drain (人才流失) ," which dealt with the problem of students and learned people who left their own countries for other countries that offered better chances for study, research, and employment. For example, according to a report from U.N., between 1962 and 1966 more than 50 percent of all engineering graduates of Iran and 14 percent of Iranian (伊朗的) scientists left their country for work abroad. Over 30percent of Chilean (智利的) engineers and 15 percent of Turkish (土耳其的)physicians also went to work in other countries. Probably the greatest brain drain occurred among young scientists who had gone abroad to study. Many of them had planned to return to their countries to teach but chose to remain in more industrialized nations where they were able to continue their work and their research in fields in which there were no job possibilities at home. The countries that attracted most of these scientists were the United States, Great Britain, Germany, France, Canada, and Australia.
Recent studies show that the brain drain to the United States may be decreasing. Many foreign scientists are going home again, and in some cases American scientists are leaving the United States for employment in other countries. The main reasons are that good jobs are becoming fewer here, money for national research has been sharply cut, and university fellowships reduced too. However, in the field of medicine the drain to the United States still goes on. Today more than one of every five American doctors is foreign-born, and several thousand foreign doctors immigrate to the United States each year. Over eighty countries have asked the State Department to send students who are skilled in important fields such as medicine back home when their study programs are over.
33. Which of the following is not the reason for "the brain drain'"?
  A. Better chances of study. B. Better research condition.
  C. Good job possibility. D. Good housing.
34. How many American doctors are foreign-born?
  A. More than 20 percent.              B. About half of them.
  C. Several thousand.                  D. About 15 percent.
35. Which is the best title for this passage?
A. How to seek a job in the USA.         B. Doctors' immigration to the USA.
C. The brain drain.                      D. A strange case.
DAC