Polyfluoroethylene
聚氟乙烯
🗣️ 情景例句
I hope to be able to join the school band.
我想加入学校的乐队。
Americans are hight mobile, and therefore may find it difficult to became deeply involued with other.
美国人的流动性，大，因此你会发现和他人深交很难。
What will be the population of these countries by the end of the twentieth century?
到20世界末较发达国家的人口将是多少？