• 2022-06-17
    两个同心导体球面,半径分别为R1、R2 (R1A: [img=23x21]1802f9683523c3a.png[/img]
    B: 0
    C: [img=46x47]1802f9683d03386.png[/img]
    D: [img=46x47]1802f9684566da1.png[/img]