• 2022-06-30
    下列变量组是一个闭回路的有( )
    A: (x11,x25,x43,x23,x41,x15)
    B: (x13,x34,x44,x42,x12,x33)
    C: (x51,x31,x42,,x53,x44,x24,x23,x32)
    D: (x13,x22,x34,x12,x24,x32)
    E: (x13,x23,x32,x12,x24,x33)