1. a = 0
    2. b = 1
    3. c = 2
    4. # 1. and:与--都真才真
    5. print(a < b and c > b) #书写习惯,每组大于小于都用括号括起来,方便阅读防止歧义(运算优先级也更明显)
    6. print((a < b) and (c > b))
    7. print(a < b and c < b)
    8. # 2. or: 或--一真则真,都假才假
    9. print(a < b or c > b)
    10. print(a < b or c < b)
    11. # 3. not: 非--取反(义词)
    12. print(not False)
    13. print(not c > b)