its now or never
US /ɪts naʊ ɔr ˈnɛvər/
UK /ɪts naʊ ɔː ˈnɛvə/
短语
机不可失，时不再来, 现在或永不
used to say that something must be done now because there will not be another opportunity
示例:
•
This is our last chance to win the championship, it's now or never!
这是我们赢得冠军的最后机会，机不可失，时不再来！
•
If you want to ask her out, it's now or never.
如果你想约她出去，机不可失，时不再来。