I'll ring the hotel. I'll tell them we'll check in tomorrow
我来给旅馆打电话,通知他们我们明天入住。
Passengers with hand luggage can go straight to the departure gate to check in there.
携带手提行李的乘客可直接到登机口办理登机手续。
Come back to the hospital for a check in a month.
一个月后到医院复查。
I'm just going to check in these books at the library.
我正要去图书馆还这些书。