Pek
[化] 聚醚酮
🗣️ 情景例句
Is a letter of credit OK?
用信用卡可以吗？
No. I have been away on vacation.
是呀，我休假去了。
and they provided a striking demonstration of the potentialities hidden in instruments and apparatus.
并充分显示出了仪表和仪器的潜在力量。