Nitrococcus
亚硝化菌
🗣️ 情景例句
Yes, I went to the aerobics class today.
去了啦， 我上了有氧运动课了。
You'll hurt yourself, if you don't take care.
你不专心的话，就会伤到你自己。
Why didn't you tell me then?
为什么那时不告诉我呢？