Polycarbamate
[日]福代鋅
??? 情景例句
I'm going to miss all of you.
我會想念你們大家的。
Friends are lost by calling often and calling seldom.
交往過密過疏，都會失去朋友。
Once the oxygen content of the air had risen to 25% it was ready to burn.
一旦氧氣在空氣中的含量達到25%，它就要燃燒。