A:is being announced
B:has announced
C:was announcing
D:had been announced
下列各数﹣2,3,﹣(﹣0.75),﹣5,4,|﹣9|,﹣3,0,4中,属于整数的有m个,属于正数的有n个,则m,n的值为( )
已知数列{an}和{bn}都是等差数列,若a2+b2=3,a4+b4=5,则a7+b7=( )