问题 单项选择题 案例分析题

下图为在上海郊区一个蔬菜大棚所拍摄的照片,棚顶为黑色的尼龙网,而不是常见的白色透明的塑料或者是玻璃大棚。

在此季节,农民这样做的主要目的是()

A.增加大气逆辐射,提高夜间温度

B.减少地面辐射,防止夜间温度过低

C.增强地面辐射,提高农作物存活率

D.削弱太阳辐射,减少农作物水分蒸腾

答案

参考答案:D

解析:

结合前面分析,主要目的是削弱太阳辐射,减少农作物水分蒸腾,D对。对地面辐射不能减少或增强,B、C错。不会增加大气逆辐射,A错。

考点:人类活动对环境的改造。

单项选择题

Hippies were members of a youth movement of the 1960’s and 1970’s that started in the United States and spread to Canada, Great Britain, and many other countries. The hippies rejected the customs, traditions, and life styles of society and tried to develop those of their own. Most hippies came from white middle-class families and ranged in age from 15 to 25 years old. They thought too many adults cared about making money and little else. The term hippie may come from the word hip, which means "turned-in" or aware.

Hippies wanted a world based on love of humanity and peace. Many believed that wonderful, magical changes were about to take place. They thought these changes would happen as soon as people learned to express their feelings honestly and to behave naturally at all times. Hippies ply opposed U.S. involvement in the Vietnam War.

Many hippies lived together in small groups, working with one another and sharing possessions. Others refused to be tied down to a fixed job or home. They wandered from place to place seeking part-time work and temporary shelter. Some begged for spare change and lived in the streets or camped in parks or other public lands.

Hippies were sometimes called "flower children" because they gave people flowers to communicate gentleness and love. They let their hair grow long and walked barefoot or in sandals. Hippies attracted public attention by wearing clothing that featured unusual combinations of colors and textures. A large number of hippies used marijuana, LSD, and other drugs. Drug experiences shaped many of their symbols and ideas.

The Beatles, a popular English rock group, helped spread the hippie movement with their song. Hippie favorites included such other rock groups as the Grateful Dead and the Jefferson Airplane, singers Joan Baez and Bob Dylan, poet Allen Ginsberg, and novelist Ken Kesey. Many hippies admired Timothy Leary, a psychologist who preached salvation through the use of drugs.

In time, most hippies realized it was not easy to reform society by "dropping’out" of it. Some joined more organized political movements to work for specific social causes. Others turned to spirituality or religion. The majority simply left the hippie stage of their lives behind while trying to hold on to at least a few of the ideals that once inspired them.

Hippies gave flowers to people because they()

A. wanted a world based on love of humanity and peace

B. could not find jobs and had to sell flowers for a living

C. wanted to tell people that they were badly in need of love

D. wanted to show people that they meant no harm to them

单项选择题