A:4、8、8
B:2、4、8
C:8、16、16
D:8、0、8
如图,AB是⊙O的直径,弦CD⊥AB于点E,∠CDB=30°,⊙O的半径为3cm,则弦CD的长为( )
Private Sub Command1_Click()
Text1.Text = f(3)
End Sub
Function f(x As Integer) As String
If x = 1 Then f = 1 Else f = f(x - 1) + 2
End Function
运行程序并点击按钮Command1后,文本框Text1中显示的内容是( )