背部的

例句：

1. 1. She sat back in her chair and crossed her legs.
   她坐在椅子上，交叉着腿。
2. 2. The car backed up the driveway to let us pass.
   汽车把车停在车道上，让我们过去。
3. 3. He backed away from the crowd, feeling vulnerable.
   他远离人群，感到自己很脆弱。