起伏的英文：
ups and downs
with a wavy motion (brush stroke in painting)

参考例句：

The heave of waves
海浪起伏

free flowing contour
自然起伏的地形

The heave of the sea
海水的起伏,海浪

fluctuation of boundary layer pressure
附面层压力起伏

The movement of his chest as he breathes.
他呼吸时胸部的起伏。

I feel seasick in the heavy swell.
我在猛烈起伏的海面上感到晕船。

Marked by or moving in a wavelike form or motion; sinuous.
波状的或以波浪式运动的;起伏不平的

A ripple of laughter, voices,applause
一阵轻柔起伏的笑声、说话声、掌声.

Note that in areas of monoclinal dip the closure of a trap may not be the same as its structural relief.
值得注意的是，在只有单斜地层的构造内，圈闭的幅度可能与构造的起伏不一样。

Like black hulks, the shadows of the great trees ride at anchor on the billowy sea of grass
大树的阴影像黑色的大船停泊在波浪起伏的茫茫草海上。

ups是什么意思：
adv. 向上；在上面，在高处；起床，起来；向（或在）地势更高处；往；上涨
prep. 向上；向高处，向上游；在…上端；沿着
adj. 起床的；结束的，到点的；正在整修的；上升的，涨的
n. 上升；繁荣

On the up and up
坦率,诚实

rush up; push up
催促

Tourism is up, jobs are up, individual income is up.
旅游火了，工作机会多了，个人收入涨了。

downs是什么意思：
prep. 在…下，沿着
v. 下降，打倒
n. 潦倒；羽绒；丘陵

Down with hegemonism!
打倒霸权主义！

The sun is down.
太阳下山了。

Close down autos and you close down steel and rubber.
关掉了汽车工业你也就关掉了钢铁工业和橡胶工业。

wavy是什么意思：
a. 有波浪的,多浪的,波浪状的,波动的,不稳定的

Metalwork decorated with wavy patterns of inlay or etching.
波形花纹制品用波形花纹的镶嵌图或蚀刻画装饰的金属制品

Occasional pieces have highly figured, wavy grain.
个别几片有图案明显的波状纹路。

To decorate(metal)with wavy patterns of inlay or etching.
用波形花纹装饰以波形的镶嵌物或蚀刻来装饰(金属)