封闭用英语该怎么说

To describe something as "sealed" or "enclosed" in English, you can use the word "closed." For example:
The room was closed and sealed, with no way to get in or out.
The door to the building was closed and locked, so we had to find another way inside.
The package was closed and secured with tape, so it wouldn't open during shipping.
Another word you could use to describe something that is sealed or enclosed is "shut." For example:
The windows were shut and locked, so we couldn't escape the room.
The door to the cabinet was shut and wouldn't open, no matter how hard we tried.
The box was shut and sealed, so we couldn't see what was inside.