船的龙骨在建造过程中最先被安装。

The ___keel is the first part installed when building a ship.

强风使帆船突然倾覆了。

The strong wind made the sailboat ___keel over suddenly.

在经历这场危机后，他需要一些时间来平复自己的情绪。

After the crisis, he needed some time to ___keep his emotions.