We must act now, it's now or never.

我们必须现在行动，机不可失。

This chance for us it's now or never.

这次机会对我们来说机不可失。

This opportunity it's now or never, you must seize it.

这个机会机不可失，你一定要抓住。

You need to understand, such good things it's now or never.

你要明白，这种好事机不可失。

He told me, it's now or never, so I decided to take the risk.

他告诉我，机不可失，所以我决定冒险一试。

He seems increasingly desperate. It's now or never.

看起来它变得越来越拼命。这是生死关头。

He's is running out of energy and knows that it's now or never.

它已经快没劲儿了，知道成败在此一举。