"I can always tell a graduate class from an undergraduate class," said an instructor at a university graduate engineering course. "When I say 'Good afternoon,' the undergraduates respond 'Good afternoon.' But the graduate students just write it down." 一个教师在研究生工程学课堂上说："我一眼就能看出来哪些是本科生，哪些是研究生。

 

" "我说'下午好'的时候，本科生回答'下午好'，而研究生则把这句话记在本子上。

 

"