These days they were up at the crack of dawn.

这些天他们在破晓时就起床。

We have to get up at the crack of dawn.

我们不得不在破晓时起床。

I was born to surf. This is why I wake up at the crack of dawn every day.

我生来为了冲浪，这是我天天早晨醒来的原因。

If you don't need to get up at the crack of dawn, turn off the alarm clock.

如果你不需要破晓起床，那么关闭闹钟。

If you don't need to get up at the crack of dawn, turn off the alarm clock.

如果你不需要破晓起床，那么就关掉闹钟。