鴨子被吃掉了

來源: 於 2010-05-14 09:26:39 [舊帖] [給我悄悄話] 本文已被閱讀：次

Yes, I know what you mean.

1:x = Vf: Vduck
PI: 1-x = Vf : Vduck

so the fox (or cat) will be there to eat this duck.