• 2022-06-30
    设 [img=13x19]1803b35a89802fd.png[/img] 是正向圆周|[img=52x25]1803b35a91fb923.png[/img]. 下列积分中,积分值为零的是( ).
    A: [img=85x48]1803b35a9a958fb.png[/img]
    B: [img=59x48]1803b35aa2f24e2.png[/img]
    C: [img=54x48]1803b35aabb8fd0.png[/img]
    D: [img=83x48]1803b35ab3bc777.png[/img]
  • 举一反三