undulation
n
(a) [U] wave-like movement or appearance 波动; 起伏.
(b) [C] one of a number of wave-like curves or slopes 波状的弯曲或斜坡
The downs fell in gentle undulations to the sea. 这块丘陵地略带倾斜伸向大海.
🗣️ 情景例句
Yes, I think I can in ordinary circumstances.
是的,一般情况下,我没有问题。
When did you ener the school?
你什么时候入学的?
I joined in the march and we were marching peacefully along and then the police came up.