中国家庭有很多人在养猫或狗作为宠物, 就你日常生活中所观察的, 说一下养宠物的利与弊。根据下列表格提示写一篇80词左右的短文（开头已给出, 不计入总词数）。

advantages	Make fun, a kind of exercise
disadvantages	Make people scared and annoyed, Attack people, bark loudly at night, Hurt people

    A lot of people in cities keep pets now. Keeping pets nearly becomes a common habit of modern people. But not all the people in cities like that. Why do they think so? What are the advantages and disadvantages of keeping pets?