This is the 2154th most frequent Chinese word.
循环
"循环" means "cycle" or "circulation."
Here, '循环' refers to the periodic or repeating nature of the motion.
太阳系中的行星按照一定的轨道循环运行。
The planets in the solar system orbit cyclically along defined paths.
In this sentence, '循环' denotes the recurring or iterative nature of processes or events.
生活中的许多事情往往是一个循环的过程。
Many things in life are often cyclic processes.
Here, '循环' is part of the phrase '循环利用' (recycling), indicating the repeated usage of resources for sustainability.