Polyacetylene
聚乙炔
🗣️ 情景例句
Tom doesn't have a steady girlfriend at the moment.
汤姆眼下还没有一个已确定关系的情侣。
His bad English is a bar to his getting a job.
他的英语很差，这是他找工作的一个障碍。
She intends to make teaching her profession.
她想以教书为职业。