手形指针

例句：

1. 1. He held the ball with his left arm.
   他用左臂拿着球。
2. 2. She stretched her arms out to touch the sky.
   她伸展双臂，想要触摸天空。
3. 3. The arm of a chair is designed to support your back when you sit down.
   椅子的扶手设计成当你坐下时支撑你的背部。