What do people who frequently travel internationally do to kill time on airplanes?

Read a book when you are bored and sleep when you feel sleepy. Because the train travel is slower, but the flight is very fast. Normally, the time will not exceed 10 hours. So after watching for two hours, the rest of the time was spent sitting in the seat, and after a short sleep, we basically arrived at the destination. Then there are other things to do after arriving, so naturally you need to rest and recuperate on the plane so that you can have more energy for the next work.