Undulations
(undulation 的复数) n. 波动, 波状弯曲, 起伏\\n[医] 波动
🗣️ 情景例句
I don't know how to solve the problem. Will you help me out?
我不知道该怎么解决这个问题。你能帮我吗？
Janet got mad when she heard the false story.
珍妮特听到了虚伪的话，因而大发雷霆。
But this does not matter, for, as he has often remarked, one is never too old to learn.
但这没有关系，因为正如他常说的那样，人要活到老学到老。