March20thisWorldWaterDayeveryyear．AccordingtoareportfromtheUnitedNations，morethanhalfoftheworld'smajorrivershaveseriouswaterlossandarepolluted．TheYellowRiver，theworld'sfifthlongestriver，wateredsomeofthe

Question

March 20th is World Water Day every year．According to a report from the United Nations，more than half of the world's major rivers have serious water loss and are polluted．
The Yellow River，the world's fifth longest river，watered some of the oldest farms  on earth．（46）___   Its source（源头）on Qinghai-Tibet Plateau is drying up．In most  of the past 35years，it didn't reach the sea．
The Nile in Egypt，running 6，650km，is the longest river in the world．（47）___  Now it is down to 2billion m³or so．Australia's Murray River reaches the sea only every other year．One fifth of America's Rio Grande has no water，either．
（48）___
Mostly it's damming（筑坝）and global warming that make rivers dry．（49）___   Now about 45，000of them lie across the world's rivers．They hold back around 15% of the world's fresh water from running to the sea．
（50）___  Warmer weather takes water away．The glacier（冰川）are becoming smaller．The source of the Yellow River is drying up because of it．Global warming has had certain effects on water sources．Droughts （干旱） happening around the world make people pay more attention to this fact．

A．Dams provide fields with water and make power．

B．How does it happen？

C．It used to carry 32billion m³of water a year．

D．But now it has a serious problem．

E．Global warming is making things worse．

Answer 1

46．D．推理判断题．根据The Yellow River，the world's fifth longest river，watered some of the oldest farms  on earth．--Its source（源头）on Qinghai-Tibet Plateau is drying up．In most  of the past 35years，it didn't reach the sea．可知本段主要讲了有关黄河的有关内容，前面说黄河是世界上第五大河，浇灌着地球上最古老的农田，后面又介绍在过去的35年里，黄河里的水就没有流到大海里，据此可以判断出黄河遇到了一个大问题，所以应该选择D，But now it has a serious problem．故选D．
47．C．推理判断题•．根据Now it is down to 2billion m³or so．可知上文是说尼罗河以前的流量，所以应该选择C，It used to carry 32billion m³of water a year．故选C．
48．B．推理判断题．根据Mostly it's damming（筑坝）and global warming that make rivers dry．可知这里是说了造成水资源缺乏的原因，所以用选项B，How does it happen来提出问题．故选B．
49．A．推理判断题•．根据Mostly it's damming（筑坝）and global warming that make rivers dry，可知造成水资源缺乏和污染的主要原因是由于筑坝和全球变暖，所以此空说明筑坝产生的目的，所以应该选择A，Dams provide fields with water and make power．故选A．
50．E．推理判断题．根据Global warming has had certain effects on water sources，可知全球变暖对水的源头产生一定的影响，所以此句黄河的问题就因为这种原因．所以选择E．Global warming is making things worse．故选E．