题目内容：
When people in developing countries worry about migration, they are usually concerned at the prospect of their best and brightest departure to Silicon Valsey or to hospitals and universities in the developed world. These are the kind of workers that countries like Britain Canada and Australia try to attract by using immigration rules that privilege college graduates. Lots of studies have found that well-education people form developing counting are particularly likely to emigrants , A big survey of Indian households in 2004found that nearly 40% of emigrants had morn than a high-school education ,compared with around 3.3%of all Indian over the age of 25. This "brain drain" has long bothered policymakers in poor counties .They fear that it hurts their economies, depriving them of much-needed skilled worker who could have taught at their universities, worked in their hospital and come up with clever new product for their factories to make
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