Allyloxy
烯丙氧基
🗣️ 情景例句
Excuse me.
失陪。
It's earier to run down the hill than go up.
下山容易上山难。
Everybody here is busy getting ready for it and buying Christmas presents.
这里的每一个人都在忙于为圣诞节做准备和忙于购买圣诞节礼物。