In modern society, there are more and more old people, do you think its benefits outweigh its disadvantages?

　　It is suggested that young adults are required to take up a period of unpaid work for the local community. Do you think its benefits outweigh its drawbacks?

　　Many people think it is important to protect the environment, but they make no effort on it themselves. Why is it and what your opinion?

　　Once children start school, teachers have more influences on their intellectual and social development than parents. To what extent do you agree or disagree?