The cold was unbelievable.

　　天氣冷極了。

　　The pressure they put us under was unbelievable

　　他們給我們施加的壓力之大超乎想象。

　　I find it unbelievable that people can accept this sort of behaviour

　　人們竟能接受這樣的行為，我震驚不已。

　　I know it sounds unbelievable but I never wanted to cheat.

　　我知道聽上去難以置信，但我從不想撒謊。

　　I still find this story both fascinating and unbelievable

　　我仍覺得這個(gè)故事既有趣又不太可信。