• 2022-06-16
    设随机变量X和Y满足[img=303x43]17e4442c4384368.png[/img],则[img=138x22]17e4442c4e7cf90.png[/img]( ).
    未知类型:{'options': ['', ' [img=11x33]17e43b6c766158c.jpg[/img]', ' [img=11x33]17e4431b48f6e37.jpg[/img]', ' [img=11x33]17e4442c165ad52.jpg[/img]'], 'type': 102}