1、L-35Christmas TreesMany Americans are busy preparing for Christmas and the winter holiday season. Buying a Christmas tree is a holiday tradition for many Americans. One study found that almost eighty percent of American homes had a Christmas tree last year. Christmas trees come in all shapes and siz
2、es. Perhaps the most famous is the huge Christmas tree near the White House in Washington, D.C. The National Christmas Tree Association represents Christmas tree growers in the United States. It reports that almost forty percent of all Christmas trees in American homes are natural. The other sixty p
3、ercent are artificial or man-made trees. Many people believe that Christmas trees come from forests. In fact, most trees are carefully grown on farms. Farmers plant and harvest Christmas trees as a crop, similar to fruits or vegetables. There are about fifteen-thousand Christmas tree farms in North
4、America. There are Christmas tree farms in all fifty states and Canada. Currently, about four-hundred-thousand hectares of farmland is in production. The industry employs more than one-hundred-thousand people. About thirty-three-million natural Christmas trees are sold in North America each year. It
5、 can take as many as fifteen years to grow a tree to a height of two meters. However, the average growing time is seven years. Traditionally, farmers grow evergreen trees for Christmas trees. Scotch pine, white pine and Douglas fir are among the most popular. Evergreen trees produce cones. Most coni
6、ferous trees have both male and female cones. The female cones are called seed cones. They hold the seeds created by fertilization. Farmers remove fertilized seeds from the seed cones and plant them. They grow into seedlings. Famers care for the young trees until they are about three to five years o
7、ld. Then famers replant them in fields. Farmers add fertilizer to the trees and remove unwanted plants. They cut the tops of the trees to control how fast the trees grow. Farmers cut other parts of the trees while they are growing. This gives the trees the traditional shape that people will like. (3
8、39 words) 圣诞树许多美国人正忙着为圣诞节和冬季假期作准备。对于很多美国人而言，买圣诞树是一个节日传统。一项研究发现，去年几乎百分之八十的美国家庭都有圣诞树。圣诞树大小和形状各不相同。或许，最著名的是位于华盛顿白宫附近的巨型圣诞树。国家圣诞树协会代表了美国的圣诞树种植者。据报道，美国家庭几乎百分之四十的圣诞树都是天然的。其余百分之六十是假的或者人造树。许多人脑认为，圣诞树来自森林。事实上，大多数圣诞树是在农场精心栽培长成的。农民把圣诞树像农作物一样种植和收获，就像水果和蔬菜一样。在北美，大约有一万五千个圣诞树农场。美国的 50 个州和加拿大都有圣诞树农场。目前，大约 40 万公顷的农场土地用于种植圣诞树。这个行业雇用了十多万人。每年，大约有三千三百万棵圣诞树在北美销售。种植一棵两米高的树可能需要多达十五年的时间。但是，平均的生长时间是七年。传统上，农民把常青树作为圣诞树来种植。苏格兰松，白松和花旗松最受欢迎。常青树长有球果。许多针叶树既有雄果又有雌果。雌果叫做种子果，它们经过受精可以长出种子。农民从种子果上取出受精的种子种植。它们长成树苗。农民在树苗长到三至五年前对其一直是精心呵护的。然后，农民将它们移到田野种植。农民为树苗施加肥料，锄掉杂草。他们砍掉树顶，以控制书的生长速度。他们也会修剪其他的部分，这样树就可以长成人们所喜爱的传统形状了。
