价格的周期性变动可以观察得到，但相当平缓。

Cyclical patterns can be observed, but movements are relatively moderate.

youdao

但是，国家人口中的一个周期性变动-自1979年实施“独生子女”政策以来造成的年轻劳动力不足，也许将抵消北京的努力。

But a tidal shift in the country's demographics-a dwindling supply of young workers as a result of the "one child" policy in effect since 1979-will counteract Beijing's efforts.

youdao

简言之，相对的和平稳定与战争动乱，呈周期性波动，是这个500年期间一个全球性的现象，这似乎与气温变动周期相关联。

In short, synchronous periods of relative peace and turbulence during those 500 years were a global phenomenon seemingly linked to temperature change.

youdao