When global warming finally came, it stuck with avengeance(异乎寻常地).In some regions, temperatures rose several degrees in less than acentury. Sea levels shot up nearly 400 feet. floodingcoastal settlements and forcing people to migrateinland. Deserts spread throughout the world asvegetation shifted drastically in North America. Europe and Asia. After driving many of theanimals around them to near extinction, people were forced to abandon their old way of lifefor a radically new survival strategy that resulted in widespread starvation and disease. The adaptation was farming: the global-warming crisis that gave rise to it happened morethan 10,000 years ago.
As environmentalists convene in Rio de Janeiro this week to ponder the global climate of thefuture, earth scientists are in the midst of a revolution in understanding how climate haschanged in the past-and how those changes have transformed human existence. Researchershave begun to piece together an illuminating picture of the powerful geological andastronomical forces that have combined to change the planet's environment from hot tocold, wet to dry and back again over a time period stretching back hundreds of millions ofyears.
Most important. scientists are beginning to realize that the climatic changes have bad a majorimpact on the evolution of the human species. New research now suggests that climateshifts have played a key role in nearly every significant turning point in human evolution: fromthe dawn of primates(灵长目动物) some 65 million years ago to human ancestors rising up towalk on two legs. from the huge expansion of the human brain to the rise of agriculture. Indeed, the human history has not been merely touched by global climate change, somescientists argue, it has in some instances been driven by it.
The new research has profound implications for the environment summit in Rio. Amongother things, the findings demonstrate that dramatic climate change is nothing new forplanet Earth. The benign(宜人的) global environment that has existed over the past 10,000 years-during which agriculture. writing, cities and most other features of civilization appeared-isa mere bright spot in a much larger pattern of widely varying climate over the ages. In fact, the pattern of climate change in the past reveals that Earth's climate will almost certainly gothrough dramatic changes in the future-even without the influence of human activity.
1.Farming emerged as a survival strategybecause man had been obliged__________.
A) to give up his former way of life
B) to leave the coastal areas
C) to follow the ever-shifting vegetation
D) to abandon his original settlement
2. Earth scientists have come to understand that climate____________.
A)is going through a fundamental change
B)has been getting warmer for 10,000 years
C) will eventually change from hot to cold
D) has gone through periodical changes
3.Scientists believe that human evolution________.
A) has seldom been accompanied by climatic changes
B) has exerted little influence on climatic changes
C) has largely been affected by climatic changes
D) has had a major impact on climatic changes
4.Evidence of past climatic changes indicates that__________.
A) human activities have accelerated changes of Earth's environment
B) Earth’s environment will remain mild despite human interference
C) Earth's climate is bound to change significantly in the future
D) Earth's climate is unlikely to undergo substantial changes in the future
5.The message the author wishes to convey in the passage is that______________.
A) human civilization remains glorious though it is affected by climatic changes
B) mankind is virtually helpless in the face of the dramatic changes of climate
C) man bas to limit his activities to slow down the global warming process
D) human civilization will continue io develop in spite of the changes of nature