The US first lady Michelle Obama gave speeches in Beijing University, which Chinese students’ heated discussions about going abroad for further study.
A. turn on
B. go down
C. set off
D. e up
网友回答
A. turn on
B. go down
(答案→)C. set off
D. e up
解析：A. turn on打开，B. go down下来，C. set off出发，动身，引发，D. e up被提出，过来，句意：美国第一夫人Michelle Obama在北京大学做了演讲，这引发了中国学生对于出国深造的热烈的讨论。所以选C。