盛衰的英文：
eat and flow
ebb and flow
the swing of the pendulum
vicissitude
wax and wane

参考例句：

wax and wane
(月的)盈亏[圆缺];[喻]盛衰

(be)in a state of flux and reflux
处于潮涨潮落状态;[喻](人、事)荣枯,盛衰

The swing of the pendulum
荣枯盛衰

The popularity of the film stars waxed and waned.
电影明星们的名望盛衰无常。

A chequered career/history/past
荣辱盛衰的事业[历史/过去

The company has undergone many ups and downs.
这家公司历经盛衰浮沉。

Every tide have its ebb.
潮水有涨落，人生有盛衰。

Life is hard．There are a lot of ups and downs in one's life.
生活是艰辛的,生活中充满了太多的盛衰与浮沉

Second, the information industries will go through boom-bust cycles, of which we have merely experienced the first.
其次，信息产业将不断经历盛衰周期，我们仅仅经历了其中第一个。

eat是什么意思：
v. 吃，喝；用餐；腐蚀

These are the eating utensils.
这些是进餐时用的器具。

Are you eating pomelo?
你们在吃柚子吗？

These are eating apples.
这些是可生食的苹果。

flow是什么意思：
v. 流动；源自，来自
n. 流；流动；流畅；连贯；大量

Exercise stimulates the flow of blood.
锻炼促进血液循环。

free flowing contour
自然起伏的地形

The flow of fluid is steady.
液体的流动很稳定。

ebb是什么意思：
n. 衰落 ；减少；退潮
v. 衰落 ；减少；退潮

Every tide has its ebb.
潮起必有潮落

Every tide hath its ebb
兴盛之日必有衰退之时

Every tide hath its ebb.
兴盛之日必有衰退之时。