Cavities
n. 腔, 洞( cavity的名词复数 ); （龋齿的）洞
✅ 同义词
🗣️ 情景例句
Can you weigh this for me?
你能帮我称称这（包裹）吗？
Sure. We are friends since primary school.
当然，我们从小学就是朋友了。
This increases their air-resistance and reduces the shock of impact when they hit the ground.
这样就加大了空气阻力，并减少了它们着地时冲击力带来的震动。