宇航员在月球表面以速率v竖直上抛一个小球，经过t秒落回原地，已知月球半径为R,如果要在月球上发射一颗绕月球表面运行的人造卫星，则卫星的线速度为        ；

以上程序段运行的结果是：______.
Dim a(-1 To 5) As Boolean
Dim flag As Boolean
flag = False
Dim i As Integer
Dim j As Integer
Do Until flag = True
For i = -1 To 5
j=j+1
if a(i)= False Then
a(i)= True
Exit For
End If
If i = 5 Then
flag = True
End If
Next
Loop
Print j

A．20

B．7

C．35

D．8