不要遇到一点困难就打退堂鼓。

Don't back up the moment you run up against a little difficulty.

不能遇到点困难就打退堂鼓呀。

You can't give up the moment you run up against difficulty.

他们的赞助人在最后时刻打了退堂鼓。

Their sponsors pulled back at the last minute.