Underframing
底层框架的材料或结构部件
🗣️ 情景例句
I was teaching music,
我当时教音乐，
We have some reports to show you for background information.
我们还有一些报告向你介绍背景资料。
My holidays passed quickly, but I did not send cards to my friends.
假期过得真快，可我还没有给我的朋友们寄过一张明信片。