undergear

例句：

1. 1. The soldier's undergear was designed to protect him from the elements.
   士兵的装备设计用来保护他免受恶劣天气的影响。
2. 2. The military used this undergear to improve its combat effectiveness.
   军队使用这种装备来提高其战斗效率。
3. 3. The undergear is essential for any soldier who wants to stay ahead of the game.
   对于任何想要在比赛中保持领先的士兵来说，装备是必不可少的。