Many high schools ask their students to spend a certain number of hour _volunteering_ every day.

分类: 作业答案 • 2021-12-28 16:21:00

问题描述：

Many high schools ask their students to spend a certain number of hour _volunteering_ every day.
这是一道选正确形式填空,volunteering.但是我实在是看不懂为什么吖~

答

sb.spend + 时间+（in）doing sth.某人花费时间做某事,是固定搭配