The U.S. has 11 active aircraft carriers and 9 amphibious assault ships which are essentially smaller aircraft carriers.

美国有11艘现役航空母舰和9艘两栖攻击舰，其本质上是小型航空母舰。

There are a total of about 20 active aircraft carriers in the world, and the US has half of them, and it's building more.

世界上共有约20艘现役航空母舰，美国占一半，而且它还要建造更多。