Pentachloroethane
五氯乙烷
🗣️ 情景例句
Don't worry about it. It's nothing.
别担心，没事儿。
After forty years teaching English he thinks it's time to call it a day.
他教英语四十年，认为该退休了。
Though a number of descents have been made, much of it still remains to be explored.
人们多次进入洞内探险，但至今尚有不少东西有待勘探。