this is the Agriculture Report.Americans love Christmas trees.The National Christmas Tree Association saysmore than 35 million of themwere bought last year in the United States.In large American cities,many people buy trees that have already been cut.But many people drive to a tree farmand cut them own tree.Some buy one from a catalogue or online,the tree is then delivered to their home.The National Christmas Tree Associationrepresents growers and sellers of most of the farm-grown Christmas tress in the United States.It estimated that 10.9 million artificial treeswere sold in 2012,compared to 24.5 million natural trees.The group says the average cost of a natural tree was $40,and about $70 for an artificial one.Most Christmas trees are now grown on farms.The trees take six to ten years to grow.In some states, fewer than half of the planted treessurvived the weather conditions to become Christmas trees.To make sure there is always a supply,farmers usually plant one to three new saplingsfor every tree they cut down.The Christmas Tree Association says40 percent of people who bought natural trees last yearchose them at a farm and cut the tree themselves.The Association says real trees are better for the environment,that is because as Christmas trees grow,they collect carbon dioxide and other gaseswhile supplying fresh oxygen.The trees also protect water supplies.Christmas trees are grown on soilthat does not support other crops.Some people throw away their natural treewhen the holiday season ends.But many People recycle them.There are many ways to do this.Christmas trees can be cut up to be used as fertilizer.They can also be cutand used to provent the wearing down of soil.Christmas trees helped many communities near the oceanfollowing tropical Storm Sandyon the eastern coast of the United States.They were placed near large hills of sandto prevent the sand from blowing away.Artificia trees which come mostly from Chinacan be reused for years.Families use them for an average of six to nine yearsbefore throwing them away.These trees can remain in a landfill for hundreds of years.And that's the Agriculture Report from VOA Special English.更多听力请访问51voa.com