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【单选题】
Himalaya' s Receding Glaciers The great majority of the world's glaciers appear to be declining at rates equal to or greater than long-established trends, according to early results from a joint NASA and United States Geological Survey (USGS) project designed to provide a global assessment of glaciers. At the same time, a small minority of glaciers are advancing. Scientists monitor only a few of India's vital glaciers, which are receding by as much as 100 feet each year. Billions of people in China and the Indian subcontinent rely on South Asia's Himalayan glaciers the world's largest store of fresh water outside the polar ice caps. The massive ice floes feed seven of the world's greatest Asian rivers in one of the world's most densely populated regions. Yet as global climate change slowly melts glaciers from Africa to the Andes, scientists say the glaciers in the Himalayas are retreating air a rate of about 33 to 49 feet each year—faster than in any other part of the world. In the Himalayas, the Gangotri Glacier, one of India's largest, is entitled to an even more dubious distinction. Recent studies reveal that the Gangotri, which forms a mass of ice about 18 miles long, is retreating at a rate of more than 100 feet a year. But according to government officials and environmental groups like Greenpeace, very little has been done in the way of a rigorous scientific study. Scientists are monitoring glacial melting on only a handful of the 7,000 glaciers that cover the Indian Himalayas. While ice reflects the sun's rays, lake water absorbs and transmits heat more efficiently to the underlying ice, kicking off a feedback that creates further melting. And at such a rapid retreat, a gradual increase in droughts, flash floods, and landslides are not the only issue to worry about, say environmentalists. Glacier changes in the next 100 years could significantly affect agriculture, water supplies, hydroelectric power, transportation, mining, coastlines, and ecological habitats. Just when power companies are planning more energy sources to power India's growing economy, a rising level of sediment in regional rivers is creating havoc for many grids. 'The power grid in Uttarkashi is constantly breaking down and that's because of the rise in sediment in the water being used at the hydro-power projects,' says Joseph Thsetan Gergan from the WADIA Institute of Himalayan Glaciology, a part of the Indian Department of Science and Technology. 'When the power breaks down, the people blame the Geological Survey of India or the Central Water Commission for not doing its work properly, but that's like thinking of digging a well when your house is already on fire.' While the Gangotri has been retreating since measurements began in 1842, the rate of retreat, which was around 62 feet per year between 1935 and 1971, has almost doubled. Global warming is causing Himalayan glaciers to rapidly retreat, threatening to cause water shortages for hundreds of millions of people who rely on glacier-dependent rivers in China, India and Nepal. In northwest China, the Qinghai Plateau's wetlands have seen declining lake water levels, lake shrinkage, the absence of water flow in rivers and streams and the degradation of swamp wetlands An added difficulty, says Mr. Gergan, is the lack of a sustained research effort since the 1970s. The Indian government's own recommendations, issued in March 2002 by the standing committee on Science and Technology, noted that glacial melting required immediate implementation of a program to measure and monitor the changes to the Gangotri and its impact on the Ganges river systems. 'It's not enough to just note the fact that the glaciers are melting,' Gergan says. 'The impact of that is not being focused on at all.' Melting ice may cause serious problems and all these impacts will change with time.
A.
Y
B.
N
C.
NG
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【单选题】我国卫生部规定:饮用水标准是,每1mL饮用水中
A.
细菌总数不得超过3个
B.
细菌总数不得超过100个
C.
细菌总数不得超过3000个
D.
大肠菌群数不得超过100个
E.
大肠茵群数不得超过3个
【判断题】为什么混凝土浇筑后要进行养护?常用的养护方法有哪些? 答:混凝土中水分蒸发过快,出现脱水现象,使已形成凝胶体的水泥颗粒不能充分水化,不能转化为稳定的结晶,缺乏足够的黏结力,从而会在混凝土表面出现片状或分状剥落,影响混凝土的强度。还有就是水分过早的蒸发还会产生较大的收缩变形,出现干裂纹,影响混凝土的整体性和耐久性。所以浇筑后的混凝土要进行养护。 养护方法有:自然养护、蒸汽养护、蓄热养护等。
A.
正确
B.
错误
【单选题】我国卫生部规定:饮水标准是,每100ml饮用水中:
A.
细菌总数不得超过3个
B.
细菌总数不得超过100个
C.
细菌总数不得超过3000个
D.
大肠菌群数不得超过3个
E.
大肠菌群数不得检出
【单选题】新生和在校学生应征参加中国人民解放军 ( 含中国人民武装警察部队 ) ,学校保留其入学资格或学籍至退役后几年( )
A.
1
B.
2
C.
3
D.
4
【单选题】已知事件A与B互不相容,P(A)>0,P(B)>0,则
A.
P( )=1
B.
P(AB)=P(A) ·P(B)
C.
P(AB)=0
D.
P(AB)>0
【简答题】根据GB5749-2006生活饮用水卫生标准的要求,细菌指标为()。 (A) 细菌总数<100CFU /ml,总大肠细菌总数<3个/L,游离余氯为0.05~0.3mg/L (B) 细菌总数<100CFU/ml,总大肠细菌群每100ml水样中不得检出,游离余氯为0.05~0.3mg/L (C) 细菌总数<100CFU/ml,总大肠细菌群每100ml水样中不得检出,游离余氯(适用于加氯消毒)在于水接触3...
【单选题】根据GB5749-2006,生活饮用水卫生标准的要求,细菌指标为( )。
A.
细菌总是<100 cfu/ml,总大肠菌群<3个/L,游离余氯为O.05—0.3mg/L
B.
细菌总数<100cfu/ml,总大肠菌群每100ml不得检出,游离余氯为0.05一0.3mg/L
C.
细菌总数<100cfu/ml,总大肠菌群每100ml不得检出,游离余氯(适用于加氯消毒)在与水接触30分钟后应出厂水中不低于O.3mg/L,管网末梢水中不应低于0.05mg/L
D.
细菌总数<100 Cfu,mI,总大肠细菌总数<3个/L,游离余氯(适用于加氯消毒)在与水接触30分钟后应不低于0.3mg/L
【单选题】已知事件A与B互不相容,P(A)>0, P(B)>0,则
A.
B.
P(AB)=P(A)P(B)
C.
P(AB)=0
D.
P(AB)>0
【多选题】为保证建筑物室内有良好的学习、工作和生活的环境,在我国南方地区,屋顶的隔热是建筑物必须采用的措施。常采用的构造做法有
A.
实体材料隔热屋面
B.
架空隔热屋面
C.
蓄水隔热屋面
D.
种植隔热屋面
E.
铝架隔热屋
【单选题】青春期早期生长发育的主要特点是()。
A.
阴毛萌出
B.
出现第二性征
C.
生长突增
D.
出现月经初潮
E.
出现首次遗精
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