Polyacetylen
聚乙炔; 聚乙炔
🗣️ 情景例句
Here you go, sir.
可以，先生。
What will you do to help protect our environment from being seriously polluted?
你将为帮助保护我们的环境免遭到污染做些什么呢？
I can't read it!
我看不懂这封信，