1. IF

If...Then...ElseIf...Then...End If

If a>90 Then
    ...
ElseIf a>80 Then
    ...
Else
    ...
End If

2. Select Case

Sub test2()
    Dim score As Integer
    score = 53
    Select Case score
        Case Is >= 90
            Debug.Print "优"
        Case Is >= 80
            Debug.Print "良"
        Case Is >= 60
            Debug.Print "中"
        Case Else
            Debug.Print "差"
    End Select
End Sub

如果需要在Case条件中使用闭合区间，即同时出现大于且小于的情况，如上例中，大于60且小于70。则需要使用两个Is语句，中间用逗号隔开：

Sub test2()
    Dim score As Integer
    score = 53
    Select Case score
        Case Is >= 90
            Debug.Print "优"
        Case Is >= 80
            Debug.Print "良"
        Case Is >= 60, Is <= 70
            Debug.Print "中"
        Case Else
            Debug.Print "差"
    End Select
End Sub