Undulations
(undulation 的复数) n. 波动, 波状弯曲, 起伏\\n[医] 波动
🗣️ 情景例句
You should save some money in case of urgent need.
你应该存点钱以备不时之需。
Yesterday was such a beautiful day we decided to go for a drive.
昨天是如此美好的一天，我们决定开车出去。
The wooducutter was standing next to a fallen tree, with lots of small pieces of wood in front of him.
伐木工人正站在一棵倒下的树旁，他的前面有很多小片的木头。