已知B的ASCII码为66，以下程序统计由键盘输入的字符串中各英文字母的使用次数 Dim pp (65 To 90) For i = 65 To 90 pp(i) =0 Next x$ = InputBox(" Enter a string", x$ ) x$ = UCase$ (x$) For i = 1 To Len (x$) n =Asc(Mid$ (x$, i, 1) ) If n＞= 65 And n＜ = 90 Then 【11】 End If Next For i = 65 To 90 Ifpp(i)＞0Then Print Chr$ (i) ; pp (i) End If Next