d
to the concert?
(D)
When global warming finally came, it stuck with a vengeance. In some regions, temperatures rose several degrees in less than a century. Sea levels shot up nearly 400 feet, flooding coastal settlements and forcing people to migrate inland. Deserts spread throughout the world as vegetation shifted drastically in North America, Europe and Asia. After driving many of the animals around them to near extinction, people were forced to give up their old way of life for a radically new survival strategy that caused widespread starvation and disease. The adaptation was farming: the global-warming crisis that gave rise to it happened more than 10,000 years ago.
As environments convene in Rio de Janeiro this week to ponder the global climate of the future, earth scientists are in the midst of a revolution in understanding how climate has changed in the past – and how those changes have changed human existence. Researchers have begun to piece together an illuminating picture of the powerful geological and astronomical forces that have combined to change the planet’s environment from hot to cold, wet to dry and back again over a time period stretching back hundreds of millions of years.
Most importantly, scientists are beginning to realize that the climatic changes have had a major effect on the evolution of the human species. New research now suggests that climate changes have played a key role in nearly every significant turning point in human evolution: from the dawn of primates some 65 million years ago to human ancestors rising up to walk 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, some scientists argue, it has in some instances been driven by it.
The new research has profound implications for the environmental summit in Rio. Among other things, the findings demonstrate that dramatic climate change is nothing new for planet Earth. The good global environment that has existed over the past 10,000 years – during which agriculture, writing, cities and most other features of civilization appeared – is a 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 shows that Earth’s climate will almost certainly go through dramatic changes in the future – even without the influence of human activity.
87. Farming came out as a survival strategy because man had been required .
- to give up his former way of life
- to leave the coastal areas
- to follow the ever-shifting vegetation
- to give up his original settlement
88. Earth scientists have come to understand that climate .
- is going through a fundamental change
- has been getting warmer for 10,000 years
- will eventually change from hot to cold
- has gone through periodical changes
89. Scientists believe that human evolution .
- has seldom been accompanied by climatic changes
- has exerted little influence on climatic changes
- has largely been affected by climatic changes
- has had a major effect on climatic changes
90. Evidence of past climatic changes indicates that .
- human activities have accelerated changes of Earth’s environment
- Earth’s environment will remain mild despite human interference
- Earth’s climate is bound to change significantly in the future
- Earth’s climate is unlikely to undergo substantial changes in the future
Section C (1’ * 5 = 5’)
Directions: Read the following text and choose the most suitable heading from the list for each paragraph. There is one extra heading which you do not need.
|
A.
A general sleep rule B. The importance of sleep C. A funny sleeping example D. Different levels of sleep E. The time we need for sleep AB. Different states of sleep |
91.
Sleep, as we know, is important to us because it helps restore tired organs and tissues in our body. But how much sleep do we actually need?
92.
For most of us, eight hours seems to be about the right amount. Yet we know that there are a great many people who get along perfectly with less sleep and some who may even need more. A great deal depends on the way we live. But a good general rule to follow is to sleep as long as we have to in order to feel happy and be able to work at our best when we are awake.
93.
There are actually different levels of sleep. There is a deep sleep and a shallow sleep. In a shallow sleep our body does not get the same kind of rest as it gets in a deep sleep, so that after eight hours of a shallow sleep we may still feel tired. But a short deep sleep can be very restful.
94.
Alexander the Great was able to get a deep sleep whenever he needed it. Once, during the night before an important battle, he remained awake longer than anyone else. Then he wrapped himself in a cloak and lay down on the earth. He slept so deeply that his generals had to wake him three times to give command to attack!
95.
Normally when we go to sleep, our “sleep center” blocks off nerves so that both our brain and our body go to sleep. One prevents us from wanting to do anything and the other makes our internal organs and limbs go to sleep. But someone will fall asleep (brain sleep) and keep on marching, because his body is not asleep!
第Ⅱ卷