Polyacetylenes
多炔
🗣️ 情景例句
I beg your pardon.
对不起。
Have you got that?
你明白我的意思吗？
Both planes were going to take off on July 25th, but Latham failed to get up early enough,
两天飞机都打算在7月25日起飞，但莱瑟姆那天起床晚了。