题目

统计不同单词个数：在Text1中输入一行单词，单词和单词之间用1个空格或标点符号隔开，单击“统计”按钮，在Text2中输出单词的个数，单词区分大小写，句子以符号结尾，程序运行界面如下图所示，部分程序代码如下： k=0：s = Text1.Text For i = 0 To Len(s)-1      ①     If ch >= "a" And ch <= "z" Or ch >= "A" And ch <= "Z" Then     word = word + ch   Else     For j = 1 To k       If     ②     Then Exit For     Next j     If      ③    Then       k = k + 1       a(k) = word     End If     word = ""   End If Next i Text2.text=str(k) 则①②③处的代码为（   ） A . ①ch = Mid(s, i, 1) ②a(i) = word            ③ j <= k B . ①ch = Mid(s, i, 1) ②a(j) = word            ③ j <= k C . ①ch = Mid(s, i+1, 1) ②a(i) = word             ③ j > k D . ①ch = Mid(s, i+1, 1) ②a(j) = word             ③ j > k 答案：D

查看本题答案和解析