《大学英语》(上外版)第3册辅导(2)

Unit3 Why I Teach重点及疑难攻破: 1.puzzle:v.迷惑;苦思。n.困惑。例如: (1)I keep puzzling over his strange behavior.我苦苦地思考他的奇怪行为。(2)No one has yet succeeded in explaining thepuzzle of how life began.迄今仍无人成功地解释生命起源之谜。