Now, really just skim the surface this time, ladies.

现在轻触地板。

NASA astronauts visited the surface of Earth's moon six times between 1969 and 1972.

美国宇航局宇航员在 1969 年至 1972 年间六次造访地球月球表面。

That means the charge inside the Gaussian cylinder equals the surface charge density times the  area of one end.

这意味着高斯圆柱内的电荷等于表面电荷密度乘以一端的面积。

On the right-hand side of the equation we can substitute the surface charge  density times the area of just one end.

在等式的右边，我们可以用表面电荷密度乘以一端的面积来代替。