up-and-down

例句：

1. 1.The waves were up and down all night.
   整晚海浪都在上下起伏。
2. 2. The car was up and down the road.
   汽车在道路上来回摇摆。
3. 3.His mood was up and down like a pendulum.
   他的情绪像摆钟一样时高时低。