I promise to tell you everything one day,我保证总有一天我会告诉你一切

promise to保证

I promise to return your bicycle on good condition.

我答应一定完好无损地还你的自行车。

Your brother's life may depend on it.你哥哥可能就命悬于此

depend on依赖；依靠；取决于；随 ... 而定

We depend on the radio for news.

我们靠收音机听新闻。

We can depend on his arriving here on time.

我们可以相信他会准时到来。

Well, that's why no one can find out about us, David.所以才不能让任何人发现我们的事情

find out发现；找出来；揭发

You can find out many advantages in urban life.

你会发现都市生活中有许多便利之处。

I am trying to find out experience in teaching.

我在摸索教学经验。