Python的if....else嵌套

score = 20
if score >= 60:
    print("你已经及格")
    if score >= 80:
            print("你很优秀")
    else:
            print("你只是一般般")
else:
    print("不及格")
    if score < 30:
            print("学渣")
    else:
            print("还能抢救一下")
print("程序结束")