Polyethylenamine
聚乙烯胺
🗣️ 情景例句
But you had to be good at math.
但是你数学一定很好。
We would like to point out that delivery before Christmas is essential and hope you can offer us that guarantee.
我们想指出圣诞节前交货很重要并希望贵方能就此向我们作出保证。
Its origin is still a mystery now.
它的起源至今仍是个谜。