将过程补充完整,实现对输入成绩的评定:在文本框text1中输入一个百分制成绩,单击command1按钮,标签label1显示成绩评定结果(成绩评定标准是:90 ~ 100为“优秀”, 80 ~ 89为“良好”, 60 ~ 79为“中等”, 60以下为“不及格”)。(答题时,每个空单独占一行)Private Sub Command1_Click()___(1)___ [填空1] Case Me.text1___(2)___ [填空2]Label1.Caption = "优秀"Case Is >=80Label1.Caption = "良好"Case Is >=60Label1.Caption = "中等"Case Is < 60Label1.Caption = "不及格"___(3)___ [填空3]End Sub