英语语法分析

The sky began to darken as the storm approached.

暴风雨来临时天空变得黑沉沉的。

《牛津词典》

Please trim my eyebrows and darken them.

请把眉毛修一下，再画深一点。

Please darken the blue paint with black paint.

请在蓝漆里掺上点黑漆。