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 __1__ needed supplies of highly trained personnel to­___2____ 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. 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 ___3___ 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 ___4___ 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 ___5___ to the new laws of the international market in knowledge. Recent studies ___6____ 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 ___7____ there is an urgent need for developing countries which send students abroad to give ___8____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 ___9_____ administrative procedures to encourage them to return. If they do not do this, the brain drain is ___10______ to continue.