Polyacetylene
聚乙炔
🗣️ 情景例句
Oh. I have the key. Grandpa sent it to me.
啊。钥匙在这里。爷爷寄来给我的。
How did you get so dirty?
你为什么弄得这么脏？
He says that all this happened after I started work.
他说，这一切都是在我开始工作后才发生的。