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Dong Xuhui, director of the sandstorm research group under the administration, said the sandstorm that invaded Beijing this week was the most severe since the group began conduction sandstorm research in 1995. "In some sandstorms in the Inner Mongolia Autonomous Region, visibility had been lowered to less than 1 meter," Dong said.
The administration's satellite sandstorm supervision system showed that sand and dust drifted at about 2,500 to 3,500 meters above the ground, affecting Beijing for 51 consecutive hours. "The sand and dust particles in the air are relatively small, so they could easily invade people's breathing systems." Dong said, "So it is better to stay indoor in such weather."
Unfortunately, there are no effective ways to stop or decrease the frequency of sandstorms in the near future. Gao Jixi, a researcher with the China Environmental Science Institute, suggested that the government address that the overall problem as part of its environmental protection policy.
Though protective forests in North China are expected to grow soon, Gao said that drifting sands at high altitudes could still invade most cities. "We should consider the environment in northern and western China as a whole when adopting related environmental protection policies," Gao suggested.
He said governments in the relevant provinces and autonomous regions should speed up their industrial restructuring and firmly put a stop to industrial practices that harm the environment. Gao said some hasty tree planting activities should also be stopped because many of tree species have now been found not to match the local soil. "Planting more trees does not mean the improvement of the environment," he said.
Gao was invited to present an environmental report to premier Zhu last year. Gao had advocated the building of a large ecological system in northern and western China to resist sandstorm.
He objected to environmental stress caused by humans interfering with nature. "We should respect nature's rules by restoring the original ecological systems in those regions." Gao said. Following that principle would be the best way to fight sandstorms, he added.
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What could be expected as a result of Jenny's efforts？
Part A
Directions: Read the following four texts. Answer the questions below each text by choosing A, B, C or D . Mark your answers on ANSWER SHEET 1.
El Nino is the term used for the period when sea surface temperatures are above normal off the South American coast along the equatorial Pacific, sometimes called the Earth's heartbeat, and is a dramatic but mysterious climate system that periodically rages across the Pacific.
El Nino means "the little boy" or "the Christ child" in Spanish, and is so called because its warm current is felt along coastal Peru and Ecuador around Christmas. But the local warming is just part of an intricate set of changes in the ocean and atmosphere across the tropical Pacific, which covers a third of the Earth's circumference. Its intensity is such that it affects temperatures, storm tracks and rainfall around the world.
Droughts in Africa and Australia tropical storms in the Pacific, torrential rains along the Californian coast and the Peruvian deserts have all been ascribed to the whim of El Nino.
This at least is the theory, and it has worked pretty well over the past century, with El Nino occurring about every three to five years and La Nina in between. But there have been some baffling developments in recent years. For one thing, El Nino has returned three times in the past four years. For another, since 1976 El Nino has dominated relative to the cooler phase (La Nina). There has been only one significant La Nina, but five El Ninos, including an extremely severe one in 1982—1983 that caused damage costing 8 billion dollars. Moreover a huge pool of warm water has settled down near the dateline in the central Pacific.
Yet it is important to understand the changes if scientists are to be able to forecast the climatic effects of El Ninos with any degree of accuracy. This is not just an academic task— accurate forecasts can spell out feast or famine in many tropical countries around the world. Forecasting efforts have focused on El Nino, whose effects are generally more severe than those of La Nina.
A worrying possibility is that the changes maybe due to greenhouse warming. If so, the recent fluctuations may be an early glimpse of worse things to come.
When does El Nino happen？
Which of the following statements about the sandstorm is NOT true according to this article？
People Migrated from Asia to the Americas
From the beginning of history until about 500 years ago, the peoples of the Eastern Hemisphere and Western Hemisphere had almost no contact with each other.
Some Chinese missionaries may have reached Central America in the 400s A. D. Daring Viking explorers landed at several places on the coast of North America around the year 1000. However, accounts of their voyages were not well known, so the journeys were not followed up by others. Old European maps showed a vast blank space or fanciful islands where the Western Hemisphere lay. In fact that vast region of the world was already densely populated.
The Great Migrations
While the Ice Age still gripped the earth, people migrated from Asia to the Americas across what is now the Bering Strait, off the coast of Alaska. This strait is the narrowest point between the continents of Asia and North America. At several periods in the past, there was a "bridge" of land there. Even when there was a water barrier, the strait was only a few miles across and could easily have been crossed by small boats.
There was neither a single large migration nor a continuous flow of people from Asia. Rather, there was a series of waves of different peoples on the move. Changes in the climate in Asia may, from time to time, have forced people northeastward and across the strait. From there they would move southward toward warmer climates. Finding some areas already inhabited by those who had come earlier, they would move on, looking for a favorable place to settle.
These migrations took thousands of years. The remains of some of the early people have been found and studied. Archeologists have found remains in western North America that may date back almost 30,000 years. The people were hunters who lived in caves and hunted the giant bison, or buffalo.
Some people moved into the eastern and central areas of North America. Others drifted farther south, through Mexico and Central America and across the narrow Isthmus(地峡)of Panama. From there all South America was spread out before them.
About 14,000 years ago, some groups moved eastward into what is now Venezuela. However, the rain forests of the Amazon River basin made it difficult for people to penetrate farther into the eastern bulge of South America. Instead they kept moving to the western shoreline, pushing ever southward. Some groups settled in the Andes Mountains. Others kept moving until they could go no farther eastward into what are now Brazil and Argentina, or southward into what is now Chile.
The Development of Agriculture
The earliest traces of farming in the Western Hemisphere have been found in south-central and northeastern Mexico, along the coast of Peru, and in the southwestern United States. The first farmers planted sunflowers (for seeds), corn, beans, squash, and a variety of other crops. In the highlands of Peru the potato was the most important food. In South America and on the islands of the Caribbean, various root crops were planted, mainly manioc and other crops that were similar to sweet potatoes.
Farming began at about the same time in both hemispheres but was adopted more gradually in the Americas. The plow was not invented in the Americas partly because animals large enough to pull it did not exist there. For the same reason the wheel was not invented either. Without the plow it was not possible to plant crops on grasslands. As a result, farming had to be done on forested land that was first burned to clear off the trees. Fertilizers were also not known in this early period.
Nevertheless, agriculture was productive enough to support village life and the beginnings of towns. By the time of the arrival of Columbus in 1492, tribes as far north as the northeastern United States and Canada and as far south as Argentina were largely
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