This is the VOA Special English Education Report.

Charter schools operate with public money but without many of the rules that govern traditional public schools. In the United States the rules for charter schools differ from state to state. But in general these schools have greater freedom to decide what to teach and how to teach it.

A charter school might be independent or connected to the local public school system. It might be started by teachers, parents, community groups or, in some cases, a profit-making business.

The "charter" is a performance contract. It establishes the goals of the school and other details like how student performance will be measured. Forty-seven million students attend traditional public schools. But more than a million students attend charter schools.

And now a group of charter schools have formed the Green Charter Schools Network. The idea is to have environmentally friendly school buildings but to also go further than that.

The schools teach students to become involved in community issues that affect them and the environment. For example, young children grow crops in a school garden and learn about healthy eating. Older students help recycle waste from the cafeteria. And local schools share what they grow in community gardens with people in need.

Jim McGrath is president of the Green Charter Schools Network. He says there are about 200 "green" charter schools across the United States. He says the plan is to also include traditional public schools as well as private schools.

JIM McGRATH: "The most important thing is that every one of us -- every child, every adult -- has a responsibility that their action, every action we make has an effect on the earth that we live in. And that our natural resources are not inexhaustible. And that if we want a positive earth for future generations, we all need to make commitments to be change agents so that we don't destruct our natural resources."

The Green Charter Schools Network holds its first national conference this October in Minnesota. It will include companies and organizations like Waste Management and the United States Green Building Council. Supporters of green schools say their goal is to expand the movement across the country.

And that's the VOA Special English Education Report, written by Nancy Steinbach. Is your school doing anything special to "go green"? You can tell the world by posting a comment at voaspecialenglish.com. You can also read and listen to all of our reports and watch captioned videos. Plus, we now offer a verb phrase of the day by SMS. The service is free but standard message rates may apply. I'm Bob Doughty.

charter school: a public school operated independently of the local school board, often with a curriculum and educational philosophy different from the other schools in the system 政府支持的特许公立学校，即由家长和校方人员共同管理的公立学校

Related stories:

Importance of charter schools argued

Study of a charter school project finds big gains on tests

'Non-Formal' schools aim to fill need in Kenya's slums

US States will compete for school reform aid

(来源：VOA 编辑：陈丹妮）