According to this article, the cyclical change of the natural factors is the main factor to the Sand-Dust weather, while artificial factors make strengthen action.

分析认为，自然因子的周期变化是造成沙尘天气分布和变化的主要原因，人为因素起了加强作用。

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Though the cyclical business cycle was greatly worsened by the financial crisis, the structural problem is actually a contributing factor.

尽管经济周期在很大程度上加剧了金融危机，但结构问题才是决定性因素。

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Political observers and the public at large tend to believe that the more reliable factor is the cyclical nature of our politics, or the pendulum effect.

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