a power hand-over的用法和样例：
- The only way to climb a rope is hand over hand.
- The old lady slipped a hand over the heart.
- She got them to hand over all their money by a wicked deceit.
- There was a power cut and all the lights went out.
- The conjuror made a few passes with his hand over the hat.
- The medicine did his stomachache a power of good.