皮皮学,免费搜题
登录
搜题
【简答题】
California has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor (因素) . The number of trees larger than two feet across has declined by 50 percent on more than 46, 000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent; in parts of southern California the decline was nearly 75 percent. Many factors contributed to the decline, said Patrick Mclntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left California forests crowded with small trees that compete with big trees for resources (资源) . But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, Mclntyre and his colleagues documented a widespread death of big trees that was evident even in wildlands protected from woodcutting or development. The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed, taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt (融雪) . Since the 1930s, Mclntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt, which reduces the water supply available to trees during the dry season. ( 1 ) What is the second paragraph mainly about? A. The seriousness of big-tree loss in California. B. The increasing variety of California big trees. C. The distribution of big trees in California forests. D. The influence of farming on big trees in California. ( 2 ) Which of the following is well-intentioned but may be bad for big trees? A. Ecological studies of forests. B. Banning woodcutting. C. Limiting housing development. D. Fire control measures. ( 3 ) What is a major cause of the water shortage according to Mclntyre? A. Inadequate snowmelt .B. A longer dry season. C. A warmer climate. D. Dampness of the air. ( 4 ) What can be a suitable title for the text? A. California's Forests: Where Have All the Big Trees Gone? B. Cutting of Big Trees to Be Prohibited in California Soon. C. Why Are the Big Trees Important to California Forests? D. Patrick Mclntyre: Grow More Big Trees in California
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】已知连续的几个环比增长速度依次为为9.2%、 8.6% 、7.1%、 7、5%,则定基增长速度为( )。
A.
9、2%×8、6%×7、1%×7、5%
B.
(9、2%×8、6%×7、1%×7、5%)﹣1
C.
109、2%×108、6%×107、1%×107、5%
D.
(109、2%×108、6%×107、1%×107、5%)-1
【单选题】山东省位于中国东部沿海、()下游
A.
黄河
B.
长江
C.
辽河
D.
珠江
【单选题】()是保育员职业道德的基本要求。
A.
照顾好幼儿的全部生活
B.
热爱并尊重学前儿童
C.
教导幼儿做人的原则
D.
丰富的知识
【判断题】计算墙体工程量时,砖墙厚度以设计标注为准
A.
正确
B.
错误
【单选题】绿茶制作工艺经过的过程( )
A.
杀青-揉捻-干燥
B.
发酵-揉捻-干燥
C.
杀青-发酵-干燥
D.
杀青-干燥-压缩
【单选题】增加肋片是如何强化对流换热的传热效果的?
A.
增加传热面积
B.
增加了表面传热系数
C.
提高了温差
D.
减小了导热热阻。
【单选题】在UNIX中,一个文件的存储映像不包括 。
A.
文件目录
B.
目录文件
C.
文件索引结点
D.
文件体
【单选题】山东省的位置是 [     ]
A.
位于我国的北方,处于黄河中游
B.
位于我国东部沿海,地处黄河下游
C.
处于我国西部地区
D.
处于东部沿海,西邻山西省
【单选题】适用于纪念性建筑和特别重要的建筑的耐久年限等级是( )。
A.
一类
B.
二类
C.
三类
D.
四类
【简答题】如何增强对流换热的传热效果?
相关题目: