Underpinning
n. 基础材料, 支承结构
✅ 同义词
🗣️ 情景例句
Alexandra's coming over to help me
Alexandra就要来帮我
He already has a phonograph,but he doesn't have a radio yet.
他已经有一架留声机，但是他还没有收音机。
Dear Joan,
亲爱的琼，