at it

見at

that's it

that is the main point or difficulty

那正是要點；那正是問題所在

‘Is she going?’ ‘That's just it—she can't make up her mind.’.

“她去嗎？”“那正是問題所在——她拿不定主意。”。

that is enough or the end

夠了；好了

okay, that's it, you've cried long enough.

好了，你已經哭得夠久的了。

this is it

the expected event is about to happen

（盼望的事情）即將發生；即將來臨

this is it—the big sale.

快了——就要大甩賣了。

this is enough or the end

夠了；好了

this is it, I'm going.

好了，我就要走了。

this is the main point or difficulty

這正是要點；這正是問題所在