This is a test of commonsense. Complete the next sentence:

How to check in a car seat at the airport
Decide whether you will bring the entire car seat.
First, decide if you will bring the entire car seat, or just the seat part of it. Rear-facing and infant car seats clip into bases that are secured in cars.
Some car seats work well without the base, and for some it is required. Decide if you will bring the base on your trip.