．—________ have you been a reporter?

—For more than three years．

A．How long

B．How many

C．How soon

D．How often

下列程序运行后在立即窗口输出结果是( )。
Private Sub Form_Click()
x="a":y="b"
z=1:u=2
Debug. Print x; y, z; u
Debug. Print z; x, y; u
End Sub

A．a b 1 2
1 ab 2

B．a b 1 2
1 a b 2

C．a b 1 2
1 a b 2

D．a b 1 2
1 a b 2