Pumas never attack a human being except ^^^^^

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

热心网友

很简单，你把这句话变成正常的肯定句式“pumas may attack a human being when they are⋯⋯ ”如果去掉when显然不通。遇到你觉得靠语感难以判断的句式转为肯定句就一目了然了。

热心网友

Pumas never attack a human being except(_) cornered.答案a.beingexcept that（后加句子）才选b.when they are；except后加短语。这一道的考点主要是出现了两个BEING, 起到了干扰的作用。

热心网友

b 吧

热心网友

b