A star like the Sun has an overall magnetic strength not too different from the Earth's.

像太阳这样的恒星，其整体磁力与地球相差不大。

Over the period which Dr Penn and Dr Livingston analysed, the average magnetic strength of the irruptions has declined.

佩恩和利文斯顿博士分析表明，入侵活动的平均磁场强度已有所下降。