otherwise是什么意思

例句：

Conditions should be laid down. Otherwise it's all talk.

应该先定下条件，否则全是空谈。

Don't start giving me problems otherwise I'll have to be very unpleasant indeed.

不要开始给我找麻烦，否则我就不客气了。

Shut the window, otherwise it'll get too cold in here.

把窗户关好，不然屋子里就太冷了。