Polyethyleneimine
聚乙烯亚胺
🗣️ 情景例句
Well ...
嗯……
Comets to appear
彗星出现了
It can take as long as eight days to rig up rope ladders and to establish supply bases before a descent can be made into a very deep cave.
有时需要花费整整8天时间来搭起绳梯，建立供应基地，然后才能到一个很深的洞穴里。