问题 选择题

阅读《中国铁矿石原矿产量统计表》,其产量出现高峰值的直接原因是

A.过渡时期总路线的制定

B.中共八大经济政策指引

C.“大跃进”运动的开展

D.人民公社化运动的推动

答案

答案:C

题目分析:根据图片信息,其产量出现高峰值是在1958——1962年;A不对,过渡时期总路线的制定适用于1953——1957年;B不对,中共八大经济政策没有得到贯彻执行;D不对,人民公社化运动是在农村,而且挫伤了农民的生产积极性。联系1958年发动“大跃进”,片面要求大办工业、大办农业,C符合题意。

点评:统计图表反映历史现象的数量属性,其优点是清楚、简洁地替代了语言表达。解题的关键是把握数据变化的趋势和规律。正确的做法:第一,将所有数据串联起来进行整体的、宏观的观察。第二,发现和利用材料中的时间信息,明确历史事件时代背景。第三,结合题目要求和学习内容,确定正确选项

单项选择题
单项选择题

In the world of climate change, it is in the Earth’s cold regions where trends can most easily be seen. The cryosphere, where water is found in solid form, is among the most sensitive regions to temperature change.

The sensitivity of ice and snow to temperature changes is an early indicator of even relatively small differences, says University of Colorado at Boulder senior researcher Richard Armp. He has found that today’s receding and thinning sea ice, mountain glacier mass losses, decreasing snow extent, melting permafrost (永久冻土), and rising sea level are all consistent with warming.

Global mean temperatures have risen one degree Fahrenheit over the past 100 years. with more than half of the increase occurring in the last 25 years, observes Armp who is affiliated with the National Snow and Ice Data Center headquartered at CU-Boulder.

"As slight as that may seem, it’s enough to make a difference, " said Armp. "Now, long-term monitoring of a series of cold region, or cryospheric, parameters (参数) shows that for several decades the amounts of snow and ice around the world have been decreasing. "

The extent of Arctic sea ice is shrinking by about 3 percent per decade. but the trends are not uniform. While recent studies have indicated that the ice thickness also had decreased over several decades, new information shows that the ice may have thinned rapidly, Armp said. Examination of springtime ice thickness in the Arctic Ocean indicates that the mean ice thickness decreased 1.5 meters (4.8 feet) between the mid-1980s and early 1990s.

To mark its 25th anniversary, the National Snow and Ice Data Center has organized a special session at the 2001 Fall Meeting of American Geophysical Union, taking place this week in San Francisco, that illuminates overall changes in the cryosphere.

The session begins Tuesday and extends through Thursday afternoon, with 75 contributions from all areas of cryospheric study. Papers and posters include examinations of lake and river ice, glacier dynamics, and mass ice balance studies in polar and continental glaciers, regional and polar snow cover trends, and variations in Canadian ice cap elevations.

Studies have indicated that()。

A. the extent of Arctic sea ice has shrunk by about 3% in the past several decades

B. the mean ice thickness in the Arctic Ocean decreased 1.5 meters in the 1990s

C. the amount of ice around the world has been decreasing for several decades

D. the ice thickness decreased most rapidly between the mid-1980s and the 1990s