Our environment is very important for our lives . We need the fresh air, the clean water and so on . In the past, there were many trees around us ,the air was fresh and the river was clean.But now,people cut down many trees. Air pollution and water polloution are very serious . The environment around us becomes very terrible . We should protect our environment. First, we should plant many trees to keep water. Second , we can ride a bike or walk to the school and work.. Third , we shouldn’t throw the dirty water into the river . Fourth, we shouldn’t use the plastic bags. Finally, we can ask more people to join us.