The word “about” used in connection with the amount of the credit is to be construed as allowing a difference not to exceed more or less than the amount to which it renders. （）

A．5%, 5%

B．5%, 10%

C．10%, 10%

D．10%, 5%

下列定位方法中，可用于水下地形图测绘的有（）。

A.全站仪定位

B.经纬仪后方交会定位

C.GPS定位

D.水下声学定位