fluctuation within a narrow range meaning in English

小幅度波动
轩度波动

Besides , by reason of its long distance from jupiter , the earth can maintain a rather circular orbit . also the gravitation of the moon can stabilize the tilt of the rotational axis of the earth , thus restricting climatic fluctuation within a narrow range
另外，地球因与木星保持距离，能维持著一个几近圆形的轨道，加上月球的引力稳定了地球自转轴倾斜的角度