outline:
introduction: definition of pets, the rate of raising pets of different age groups. What are the possible reasons that the rate is various in different age groups.
Main body1: the people whose age is over 50 raise pets with a higher rate, because of the sense of lonely.
Main body2: the people whose age is below 20 raise pets simply because of the lovely appearance.
Main body3: the rich people whose age is between 35-45 purchase the expensive pets as their status symbol.
Cluclusion: some social problems:old people are lonely because their kids go out for work, which means we should pay more attention on old people. The young people cause a lot of pets become homeless dogs or cat, for they lack of the sense of responssibility. The rich people buy the pets as commodities, they use them as tools to show off, this common practice should be considered seriously.
