• 2022-07-02
    下图中杆的受力图正确的是( )[img=140x108]18033f23fb9736f.jpg[/img]
    A: [img=169x186]18033f240756bf4.jpg[/img]
    B: [img=181x162]18033f24120f6a2.jpg[/img]
    C: 0
    D: 0
  • 举一反三