She tripped over which made her knees black and blue.

她摔了一跤，膝盖跌得乌青。

He was beaten black and blue.

他被打的鼻青脸肿。

I will beat you black and blue.

我要把你打得鼻青脸肿。

She beat the boy black and blue.

她把这个男孩子打得青一块紫一块。

The bruise became black and blue.

这个梨子有碰伤的黑斑。