我的祖父，一个当了一辈子农民的人，总是在黎明时分就起床了。

My grandfather, a lifelong farmer, was always up at ___the ___crack ___of ___dawn.

高速公路的噪音从黎明时分就开始了，让人根本没法睡懒觉。

The noise from the highway starts at ___the ___crack ___of ___dawn, making it impossible to sleep in.

为了看到峡谷上的第一缕阳光，我们在黎明时分就出发了。

To catch the first rays of sunrise over the canyon, we set out at ___the ___crack ___of ___dawn.