阅读下列短文，从每题所给的四个选项 （A 、B 、C  和 D ）中，选出最佳选项。

    Christmastime in the city brings forests of trees already cut and waiting to be sold. But some people like to drive to tree farms. Others wait for their trees to come to them. They order one from the pages of a catalog or on the Internet. Some say the easiest thing of all is to buy a man­made tree with Christmas lights already on it. No falling needles to have to clean up.

    The National Christmas Tree Association says 33,000,000 real trees were sold last year, compared to 9,000,000 man­made ones. Man­made trees generally cost more, but they can be reused. Most natural trees are cut up and recycled, but some people buy trees that can be planted.

    Most Christmas trees are now grown on farms instead of in forests. Twenty-one thousand tree farmers in the United States grow Christmas trees on more than 180,000 hectares. Oregon was the leading producer last year.

    Twenty-two percent of people who bought real trees last year chose them at a farm. Two percent of those people cut the trees themselves. The next most popular places were big stores like Walmart and Home Depot. Groups like the Boy Scouts also sell Christmas trees. But some people pay nothing for theirs. They steal it.

    Cornell University in Ithaca, New York, has many pretty evergreens. Some years ago, a university worker found a way to keep them there. A month before Christmas, workers treated them with “pink ugly mix”. It contains water and red food colour. The bright colour starts to disappear after about a month. It can take longer, however. Cornell decided not to use the mix this year, but the idea has spread.

下列漫画《一家人》，主要体现了吸毒者(   )

①身体外形的变化   ②内部器官的完善   ③性机能的成熟   ④产生心理矛盾

历史上“上海曾作为苏州的‘卫星’城被称为‘小苏州’，而在“20世纪20-30年代，苏州反而变成了大上海的‘卫星城’，被称为‘小上海’。造成这一局面的主要原因是（   ）