Pek
[化] 聚醚酮
🗣️ 情景例句
Don't bother me.
别惹我。
How much is this?
这个多少钱？
(A light year is the distance which light travels at 186,000 miles per second in one year,
一光年是光以每秒186，000英里的速度在一年内走的距离，