Polybutyrolactam
[化] 聚丁内酰胺; 尼龙-4
🗣️ 情景例句
They're open until nine o'clock.
他们开到九点。
Excuse me for being late.
对不起我迟到了。
It is fairly clear that sleeping period must have some function,
很清楚，睡眠必然具有某种作用。