题目

A new plan for getting children to and from school is being started by a local government in Eastern England. This could end the worries of many parents fearful for their children’s safety on the roads.     Until now the local government has only been prepared to provide bus services for children living more than three miles from their school, or sometimes less if special reasons existed. Now it has been decided that if a group of parents ask for help in organizing transport they will be prepared to go ahead, as long as the arrangement will not lose money and children taking part任何物质都是由极其微小的粒子组成，这些粒子保持了物质原有的性质，我们把它们叫做    ．一个瓶子能盛1kg水，用这个瓶子能盛    kg水银．（水银密度13.6×103kg/m3）