a = int(input("请输入你的成绩: ")) if 90 <= a <= 100: print("你的成绩等级:A") elif 80 <= a < 90: print("你的成绩等级:B") elif 70 <= a < 80: print("你的成绩等级:C") elif 60 <= a < 70: print("你的成绩等级:D") elif 0 <= a < 60: print("你的成绩等级:E")