1.Recently we hold a fierce debate about whether people in the city should keep pets or not.
2.I don't think it harmful to keep pets at home.
3.One can improve the friendship living in a dormitory.
4.We can spend some time visiting Beijing,where you can do some shopping.
5.As we all know,the 2008 Olympics have been hold in Beijing.
6.It is necessary to improve people's quality and education.
7.Not only does it help me grasp more knowledge,but also expand my horizon.
8.Only by this can we protect our environment.
9.It is because it is convenient to us to keep in touch with my family when getting into trouble that we use cellphone.
10.There are many people in the park on weekends.