Ethylethylene
丁烯-1
🗣️ 情景例句
what you were thinking about regarding going back to work.
是否打算回去工作。
It is a great art to laugh at your own misfortune.
对己之不幸付之一笑，这是一门伟大的艺术。
It's been open for several years.
它建成已有好几年了。