Underpinning
n. 基础材料, 支承结构
✅ 同义词
🗣️ 情景例句
It's OK, Susan.
太好了， Susan。
Don't be shy!
别害羞嘛！
An advertisement which begins with the magic word FREE can rarely go wrong.
凡是用“免费”这个神奇的词开头的广告很少会失败的。