问题详情

According to the passage, the problem of the developing countries will continue __________.
A.as long as the developed countries need more qualified professionals than they can educate domestically
B.as long as the developing countries are content with their present institutional structures
C.unless those countries stop sending large number of students to be trained abroad
D.if their governments fail to make administrative adjustments concerning the return procedures of their professionals请帮忙给出正确答案和分析，谢谢！