bottom jib

例句：

1. 1. The boat was sailing at thebottom of the sea.
   船在海的底部航行。
2. 2. The pilot used a bottom jib to adjust the angle of the wings.
   飞行员使用底帆调整机翼的角度。
3. 3.The crew had to use their hands tokeep the boat from drifting too faraway from the shore.
   船员们不得不用手来防止船偏离岸边太远。