Underframing
底层框架的材料或结构部件
🗣️ 情景例句
If you roughhouse with a cat, you're going to get scratched.
如果你喜欢和猫嬉戏，可能会被爪子抓伤。
What beautiful trees those are!
那些是多么美丽的树呀！
What march?
什么游行？