Windows are usually sealed off.

窗户通常是封闭的。

The areas are sealed off and ringed by troops.

这一地区被封锁了，被军队包围了。

Police and troops sealed off the area after the attack.

警察和军队在袭击发生后封锁了该地区。

Organizers sealed off the city center.

组织者封闭了市中心。

I send a love letter, sealed off with your kiss.

为我寄上一封情书，用你的吻封上信口。