Pumas never attack a human being except ^^^^^^Pumas never attack a human being except(_) cornered.a.beingb.when they are

熱心網友

很簡單，你把這句話變成正常的肯定句式“pumas may attack a human being when they are⋯⋯ ”如果去掉when顯然不通。遇到你覺得靠語感難以判斷的句式轉為肯定句就一目了然了。

熱心網友

Pumas never attack a human being except(_) cornered.答案a.beingexcept that（后加句子）才選b.when they are；except后加短語。這一道的考點主要是出現了兩個BEING, 起到了干擾的作用。

熱心網友

b 吧

熱心網友

b