It’s just that the total area of sites with positive and negative charges are roughly equal (the two are typically within a fraction of a percent of each other).
只是带正负电的区域总面积是大致相当的（差别不超过千百分之一）。
2
The exponent is a fraction or negative number.
指数是一个分数或负数。
3
Mitral septal Angle (MSA), an index of left ventricular diastolic function, was negative correlative relationship with ejection fraction (ef) in the rest.