圣诞树的老家在德国，先传到了英国，然后才是美国。它最早可以追溯到公元700年。如今每年圣诞树的产量超过3600万棵，为了让它长成我们需要的样子，园丁要修枝剪裁，下一番工夫……
when you think of christmas， one of the first things you probably think of is a christmas tree. in fact， the christmas tree is one of the most recognizable images of the season. almost everywhere you go， it is the focal point of people's holiday decoration. you pile your gifts under the tree. you gather around your tree to sing christmas carols and drink eggnog.
most people agree that the christmas tree is a german tradition， started as early as 700 a.d. in the 1800s， the tradition of a christmas tree was widespread in germany； it then spread to england and then to america through german immigrants， who settled primarily in pennsylvania.
although you might think that all people in the 1800s went out to their back yard or to the closest patch of forest to chop down their holiday tree， christmas trees have been sold commercially in the united states since the mid 1800s.
today， about 36 million christmas trees are produced each year. the majority of these trees， somewhere between 95 and 98 percent， come directly from christmas tree farms or plantations. according to the university of illinois extension， more than 1 million acres of land have been planted with christmas trees. in north america alone， there are more than 15，000 christmas tree growers.
when it comes to christmas trees， most people have a favorite shape. some of us like tall， narrow trees. others have an affinity for something more squat and plump. both the shape of the tree and density of the needles depend on shearing. to control both the width and height of a tree， growers cut off， or shear， the tip of the leading shoot of the tree. they also cut the ends of the lateral branches， to encourage the conical shape.
重点词汇
affinity n. 爱好
squat and plump a. 矮胖的
carol n. 颂歌
eggnog n. （蛋、牛奶、糖等加酒而成）蛋酒
chop v. 砍，劈，砍倒
pennsylvania n. 宾西法尼亚州