I have to leave at once
离开───leave;必须───must
I took leave and went out.───我告别后就出来了.
As a result, he had to leave.───结果他只得离开.
We didn't leave early enough.───我们离开得不够早。
She told him to leave the room at once.───她要他马上离开房间.
You have to pay on the nail before you can leave the shop with your goods.───你在带货出店前必须当场付款.
Do not leave off your overcoat; it is cold.───不要把你的大衣脱下, 天气很冷.
You must hand over your passport before you leave.───离境前必须交回护照.
I'll leave you to undertake an important mission.───我要让你承担一项重要使命.
A thousand words will not leave so deep an impression as one deed.
How about jack? We can't just leave him here.
Leave your keys at reception before departure.
Rats leave (or desert or forsake) a sinking ship.
I have to leave early today.