动滑轮为何比定滑轮省一半的力？

设有如下程序，查找并输出该数组中的最小值，请在空白处填上合适的代码，将程序补充完整。
Option Base 1
Private Sub Command1_Click()
Dim arr1
Dim Min As Integer,i AS Integer
arr1=Array(12,435,76,-24,78,54,866,43)
Min=arr1(1)
For i=2 To 8
If arr1(i)＜Min Then______
Next i
Print "最小值是:"; Min
End Sub