多项选择题

下面程序的功能是统计字符串中“广的个数,请填空。  Sub COU( )    a$="Beijing University of Technology"    Dim n AS Integer    n=Len(a$)    For i=1 To n    b$=【 】    If【 】Then x=x+1   Next i   Print "x=";x  End Sub