填空题

In the second half of the twentieth century, many countries of the South began to send students to the industrialized countries for further education. They urgently needed supplies of highly trained personnel to implement a concept of development based on modernization.
But many of these students decided to stay on in the developed countries when they had finished their training. At the same time, many professionals who did return home but no longer felt at ease there also decided to go back to the countries where they had studied.
In the 1960s, some Latin American countries tried to solve this problem by setting up special "return" programs to encourage their professionals to come back home. These programs received support from international bodies such as the International Organization for Migration, which in 1974, enabled over 1,600 qualified scientists and technicians to return to Latin America.
In the 1980s and 1990s, "temporary return" programs were set up in order to make the best use of trained personnel occupying strategic positions in the developed countries. This gave rise to the United Nations Development Program’s Transfer of Knowledge through Expatriate Nationals, which encourages technicians and scientists to work in their own countries for short periods. But the brain drain from these countries may well increase in response to the new laws of the international market in knowledge.
Recent studies forecast that the most developed countries are going to need more and more highly qualified professionals around twice as many as their educational systems will be able to produce, or so it is thought. As a result there is an urgent need for developing countries which send students abroad to give preference to fields where they need competent people to give muscle to their own institutions, instead of encouraging the training of people who may not come back because there are no professional outlets for them. And the countries of the South must not be content with institutional structures that simply take back professionals sent abroad; they must introduce flexible administrative procedures to encourage them to return. If they do not do this, the brain drain is bound to continue.

During the late 20th century, technicians and scientists who had settled down in developed countries were encouraged to work for their home countries for ().

【参考答案】

short periods