Questions 下列各 are based on the following passage. The number of postgraduate students travelling from non-EU countries to study at UK universities has fallen for the first time in 16 years, fuelling fears that the governments immigration crackdown is discouraging thousands of the brightest students from continuing their studies in Brid. Jo Beall, British Council director of education and society, said the fall would cause alarm among UK vice-chancellors (大学行政主管). 'The sector was expecting a decline in growth, but the actual reduction in postgraduate numbers is of real concern as international-students make up the m~ority of numbers in many postgraduate courses and research teams in science, technology, engineering and mathematics. ''Attracting the brightest and most ambitious postgraduate and research students is critical if the UK is to maintain its quality reputation for research,' Beall said. Universities get a third of their tuition (学费) fee revenue from non-EU students. There is growing fear among vice-chancellors that this revenue-as well as the cultural, academic and economic benefit international students bring--is being put at risk. Tim Westlake, director for the student experience at Manchester University, said students whose families relied on them working in the UK after their studies to gain experience and repay the fees were starting to look elsewhere. Last month the home secretary, Theresa May, announced that embassy staff would interview more than 100,000 applicants in an attempt to pr bogus (假冒的) ones entering the country. She also said immigrants were responsible for pushing up UK house prices. The comments followed the introduction of new limitations on students right to work during and after their studies. Beall said:' Government statistics for the first time provide real evidence that the changes to UK visa regulations may have discouraged many students from applying to the UK, and in particular postgraduate students Who are so important to the UKs research output. The UK enjoys an eXcellent reputation around the world for the high quality of our education system, so the government needs to ensure that institutions have all the support they need to attract international students who make a tremendous academic, cultural and economic contribution to the UK. ' What has caused the decline of the number of non-EU postgraduates in the UK?