Micropycnometer
微型比重瓶
🗣️ 情景例句
I have just begun to learn and my serve isn't very good.
我刚刚开始学习，发球不太好。
They've already turned on the electricity.The house is ready.
他们已经开了电.房子是准备好了的。
Walking up and down the stairs would beat any exercise machine.
上下楼梯可比什么健身器都要好。