That was why students on duty of cleaning were going to sweep a stack of chalk ends after class.

这就是放学后值日的同学总要清扫一大堆粉笔头的原因了。

youdao

That was why students on duty of cleaning were going to sweep a stack of chalk ends after class.

这就是放学后值日的同学总要清扫一大堆粉笔头的原因了。

youdao