Question

1. We are now arriving at Incheon International Airport.

2. We are now arriving in Incheon International Airport.

3. I met one of my friends at the airport.
4. I met one of my friends in the airport.
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Which preposition do we have to use, 'at' or 'in'?

Writeacher
Using "at" means somewhere in the area of the airport.

Using "in" means inside the airport somewhere.