船在波涛起伏的海浪中剧烈摇摆。The boat rolled heavily in the troughs between the waves.伟大如穆恩者，也有状态起伏的时候。Moon, as great as he is, has had some inconsistent days.我放眼绵延起伏的群山。I looked across the mountains, ridge upon ridge....

“起伏的”的英语可以翻译为：fluctuant，rolling，undulant，undulate，undulatory ...