Peroxyacetyl
nitrate [化]硝酸过氧化乙酰
🗣️ 情景例句
Don't open the door if you don't know who it is.
如果有陌生人敲门不要开门。
She asked me which one I'd like, and I said I didn't mind.
她问我要哪一个，我说哪一个都没有关系。[动词时态一致，这是中国人学习英语最头痛的一个问题。]
Half an hour later ,she woke up and began to cry.
半小时后她醒了，哭了起来。