a hank of wool的用法和样例：
- He is trying to wind a hank of wool into balls.
- A hank of cotton yarn measures 840 yards.
- wind a hank of wool into balls
- The cat flicked out a paw and drew the ball of wool towards it.
- With all of their eyes upon him, Harry reached up to the top of his head, grabbed a hank of hair, and pulled.