单击窗体时,下列程序的执行结果是()。 Private Sub Invert(By Val xstr As String,ystr As String) Dim tempstr AS String Dim I AS Integer I=Len(xstr) Do While I>=1 tempstr=tempstr + Mid(xstr,I,1) I=I - 1 Loop yStr=tempStr End Sub Private Sub Form_Click( ) Dim s1 As String,s2 As String S1="abcdef" Invert S1,S2 Print S2 End Sub
A. abcdef
B. afbecd
C. fedcba
D. defabc