Subfluoride
低氟化物, 氟化低价物
🗣️ 情景例句
People we know?
我们认识的人。
They've been married for quite a few years.
他们结婚好多年了。
He collected tetters and made copies of people's diaries.
他收集到一些信件，复印了一些人的日记。