Polyacetaldehyde
聚乙醛
🗣️ 情景例句
It's easy to pick something for my colleagues, but it's difficult for my boss.
给同事们的应该不难买，但是给老板的就难罗。
A mean boy teases the dog.
一个淘气的男孩在捉弄着狗。
I often fish for hours without catching anything.
我经常一钓数小时却一无所获，