空中掩护

例句：

1. 1. The fighter jets provided excellent air cover for the ground troops.
   战斗机为地面部队提供了极好的空中掩护。
2. 2.The pilot had to take evasive action due to the enemy's air cover.
   由于敌方的空中掩护，飞行员不得不采取规避行动。
3. 3. The bombers were able to penetrate the enemy's air cover and drop their bombs.
   轰炸机能够穿透敌人的空中掩护，投放炸弹。