题目内容
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
A reconstruction of an ancient tree from one of Earth's first forests reveals that the plants were topped with fronds(蕨类植物的叶子) and not leaves. The crown(树冠) of an ancient tree found in a place from which stone is dug out in New York has shed light on the look of the world's earliest forests believed to have thrived about 390 million years ago.
The discovery of this 390-million year-old, six-foot upper portion of an ancient tree trunk allowed scientists to create a composite picture of the entire plant when they put it together with fragments of a trunk found in the same site a year before and with tree stumps recovered more than 130 years ago. The remains have been widely reported as "evidence of the Earth's oldest forest," according to a paper published in this week's Nature.
"The basic point of this paper is two things," says lead author William Stein. "We now have clear evidence what these stumps really were," and we also have "real strong evidence of the structure of these forms."
From the fossil reconstruction, the team of scientists determined that a tree comprising all these parts could grow about 30 feet tall. According to Stein, the base would have been massive—on the order of 2.5 feet in diameter—and a large, single trunk with vertical ridges, topped by a leafless crown of a material resembling fronds on ferns(蕨类) and palms.
By piecing together the fragments, the team was able to get an idea of what forest might have looked like 390 million years ago. Stein estimates these trees would have been "fairly closely spaced," about 3 to 16 feet apart, and that they would have dropped a load of fronds from their branches onto the forest floor. Amongst these trees were likely smaller plants and shrubs. These trees likely let more sunlight through than modern-day counterparts, for their branch structures did not fan out as far, forming an umbrella-like shape.
Stein notes that the rise of forests with trees like these caused the removal of CO2 from the air and temperatures to drop, creating climates like those experienced today. The drop CO2 in levels, he says, likely led to the evolution of flat leaves on trees to attract and retain more of the gas, which plants need. Up next, he says: research will focus on "the internal structure of the plants to work out how they grew" as well as "how they functioned physiologically, particularly the relationship with CO2."
What can people know from the crown of an ancient tree found in New York？
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Section B
Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D.
听力原文： Most people who work in London get a break of about an hour for lunch. As they most live too far from home to go bark for lunch, they have to make other arrangements for their midday meal.
Many large companies have a canteen designed for their employees. In such canteens the food served is simple but adequate and although there are a variety of choices, the number of dishes is small. The employees themselves fetch their dishes from a counter at which they are served.
As there are so many people at work in London, there are numerous cafes and restaurants in every area that is not purely residential. A meal may cost anything from a modest sum to quite a few pounds, depending on the restaurant and the food chosen. Moreover, one can generally get a meal, or at least a snack, in a pub. A number of well-known caterers run popular cafes in practically every district of London. In many of these cafes there is self-service—there are no waiters or waitresses.
Many employees do not bother to go out to lunch. They bring their own sandwiches, and perhaps an apple or bread, with which they have a cup of tea, probably made in the office. This method has the advantages of being cheap and saying time in getting to a restaurant and queuing up there. In summer, many people go out and sit on a bench in a park or public square, and eat their sandwiches there. They are often able to listen to lunch-time concerts and plays, too.
(27)
听力原文： Most people picture sharks as huge, powerful, frightening animals that eat meat, ready at any moment to use their sharp teeth to attack careless swimmers without provocation. There are numerous wrong opinions, however, in this conception of sharks.
First of all, there are about 350 species of shark, and not all of them are large. They range in size from the dwarf shark, which can be only 6 inches long and can be held in the palm of the hand, to the whale shark, which can be more than 55 feet long.
A second wrong opinion concerns the number and typo of teeth, which can vary tremendously among different species of shark. A shark can have from one to seven sets of teeth at the same time, and some types of shark can have sever al hundred teeth in each jaw. It is true that the fierce and predatory species do possess extremely sharp and brutal teeth used to rip prey apart; many other types of shark, however, have teeth more adapted to grabbing and holding than to cut ting and slashing.
Finally, not all sharks are frightening animals ready to strike out at humans. In fact, only 12 of the 350 species of shark have been known to attack humans, and a shark needs to be provoked in order to attack. The types of shark that have the worst record with humans are the tiger shark, the bull shark and the great white shark. However, for most species of shark, even some of the largest types, there are no known instances of attacks on humans.
(30)
A．The woman wants to explain the experiment.B．The woman wants to observe the experimen
A．It is wrong to give more pay to the passengers.B．Don't believe them if they are payi
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