Picknometer
比重瓶
🗣️ 情景例句
I know you must be excited to go home after such a long business trip.
出差这么久，终于要回家了，我想你一定很高兴。
He must needs go whom the devil drives.
势在必行。
It is the natural frequency of emission of the hydrogen atoms in space and was discovered by us in 1951;
这个频率是空间氢原子释放的自然频率，是在1951年被人类发现的。