单选题We are restricted to a speed of 30 miles an hour in built-up areas. A. deprived B. forbidden C. required D. limited

单选题As a manager, I should know more about the hotel trade.A. businessB. industryC. exportD. training

单选题Researchers Discover Why Humans Began Walking Upright Most of us walk and carry items in our hands every day. These are seemingly simple activities that the majority of us don"t question. But an international team of researchers, including Dr. Richmond from GW"s Columbian College of Arts and Sciences have discovered that human walking upright, may have originated millions of years ago as an adaptation to carrying scarce, high-quality resources. The team of researchers from the U.S., England, Japan and Portugal investigated the behavior of modern-day chimpanzees as they competed for food resources, in an effort to understand what ecological settings would lead a large ape—one that resembles the 6 million-year old ancestor who shared in common with living chimpanzees—to walk on two legs. "These chimpanzees provide a model of the ecological conditions under which our earliest ancestors might have begun walking on two legs," said Dr. Richmond. The research findings suggest that chimpanzees switch to moving on two limbs instead of four in situations where they need to monopolize a resource. Standing on two legs allows them to carry much more at one time because it frees up their hands. Over time, intense bursts of bipedal activity may have led to anatomical changes that in turn became the subject of natural selection where competition for food or other resources was strong. Two studies were conducted by the team in Guinea, The first study was conducted by the team in Kyoto University"s "outdoor laboratory" in a natural clearing in Bossou Forest. Researchers allowed the wild chimpanzees access to different combinations of two different types of nut—the oil palm nut, which is naturally widely available, and the coula nut (可乐果), which is not. The chimpanzees "behavior was monitored in three situations: (a) when only oil palm nuts were available, (b) when a small number of coula nuts were available, and (c) when coula nuts were the majority available resource." When the rare coula nuts were available only in small numbers, the chimpanzees transported more at one time. Similarly, when coula nuts were the majority resource, the chimpanzees ignored the oil palm nuts altogether. The chimpanzees regarded the coula nuts as a more highly-prized resource and competed for them more intensely. In such high-competition settings, the frequency of cases in which the chimpanzees started moving on two legs increased by a factor of four. Not only was it obvious that bipedal movement allowed them to carry more of this precious resource, but also that they were actively trying to move as much as they could in one go by using everything available—even their mouths. The second study, by Kimberley Hockings of Oxford Brookes University was a 14-month study of Bossou chimpanzees crop-raiding, a situation in which they have to compete for rate and unpredictable resources. Here, 35 percent of the chimpanzees" activity involved some sort of bipedal movement, and once again, this behavior appeared to be linked to a clear attempt to carry as much as possible at one time.

单选题Japanese Car Keeps Watch for Drunk Drivers A concept car developed by Japanese company Nissan has a breathalyzer—like detection system and other instruments that could help keep drunk or over tired drivers off the road. The car"s sensors (传感器) check odors inside the car and monitor a driver"s sweat for traces of alcohol. An in-car computer system can issue an alert or even lock up the ignition (点火) system if the driver seems over-the-limit. The air odor (气味) sensors are fixed firmly and deeply in the driver and passenger seats, while a detector in the gear-shift knob measures perspiration from the driver"s palm. Other carmakers have developed similar detection systems. For example, Sweden"s Volvo has developed a breathalyzer attached to a car"s seat belt that drivers must blow into before the engine will start. Nissan"s new concept vehicle (交通工具) also includes a dashboard-mounted camera that tracks drivers" alertness by monitoring their eyes. It will sound an alarm and issue a spoken warning in Japanese or English if it judges that the driver needs to pull over and rest. The car technology is still in development, but general manager Kazuhiro Doi says the combination of different detection systems should improve the overall effectiveness of the technology. "For example, if the gear-shift sensor was bypassed (迂回) by a passenger using it instead of the driver, the facial recognition system would still be used," Doi says. Nissan has no specific timetable for marketing the system, but aims to use technology to cut the number of fatalities involving its vehicles to half 1995 levels by 2015. The car"s seat belt can also tighten if drowsiness is detected, while an external camera checks that the car is keeping to its lane properly. However, Doi admits that some of the technology, such as the alcohol odor sensor, should be improved. "If you drink one beer, it"s going to register, so we need to study what"s the appropriate level for the system to activate," he says. In the UK, some research groups are using similar advanced techniques to understand driver behavior and the effectiveness (效力) of different road designs.

单选题It is normal for a teacher to get angry with the student who repeats the same mistake. A. useless B. rare C. senseless D. usual

单选题{{U}}While{{/U}} we don't agree, we continue to be friends. A. whoever B. where C. Although D. Whatever

单选题12 The two banks have announced plans to {{U}}merge{{/U}} next year．

单选题According to the passage, a greenhouse is built to

单选题Since ancient times people have found various ways to preserve meat.

单选题The dogs mentioned in the passage sensed both the low booming sounds and the minor quakes following them.

单选题There is no{{U}} risk to{{/U}} public health.

单选题Acknowledged as the main cause of hay fever the pollen of ragweed is very bothersome .

单选题The factory can produce 100 bikes every day.A. makeB. applyC. completeD. compare

单选题The President made a {{U}}brief{{/U}} visit to Beijing. A. short B. working C. formal D. secret

单选题He strange clothes and make-up really astonished the people at the partyA. attachedB. shockedC. attractedD. shifled

单选题I am sure to tell you that there"s no danger.

单选题The cost of elections in the United States is borne by both the government and the private sector.

单选题 The Smog (烟雾) For over a month, Indonesia was in crisis. Forest fires raged out of control as the country suffered its worst drought for 50 years. Smoke from the fires mixed with sunlight and hot dry air to form a cloud of smog. This pollution quickly spread and within days it was hanging over neighbouring countries including Malaysia, Singapore and Thailand. When the smoke combined with pollution from factories and cars, it soon became poisonous (有毒的). Dangerous amounts of CO became trapped under the smog and pollution levels rose. People wheezed (喘息) and coughed as they left the house and their eyes watered immediately. The smog made it impossible to see across streets and whole cities disappeared as grey soot (烟灰) covered everything. In some areas, water was hosed (用胶管浇) from high-rise city buildings to try and break up the smog. Finally, heavy rains, which came in November. Put out the fires and clear the air. But the environmental costs and health problems will remain Many people from South-Eastern Asian cities already suffer from breathing huge amounts of car exhaust fumes (汽车排放的废气) and factory pollution. Breathing problems could well increase and many non-sufferers may have difficulties for the first time. Wildlife has suffered too. In lowland forests, elephants, deer, and tigers have been driven out of their homes by smog. But smog is not just an Asian problem. In fact, the word was first used in London in 1905 to describe the mixture of smoke and thick fog. Fog often hung over the capital. Sometimes the smog was so thick and poisonous that people were killed by breathing problems or in accidents. About 4,000 Londoners died within five days as a result of thick smog in 1952.

单选题Earthquake How does an earthquake start? What makes an earthquake happen? The rock of the earth's crust (地壳) may have a "fault", a kind of break in the surface. The blocks which make up the earth move, and sometimes this may cause the sides of the fault to move up and down or lengthways (纵向) against each other. When one piece of rock starts to rub on another with great force, a lot of energy is used. This energy is changed into vibrations (振动) and it is these vibrations that we feel as an earthquake. The vibrations can travel thousands of kilometers and so an earthquake in Turkey may be felt in Greece, What to do during an earthquake? At school As soon as the earthquake starts, students should get under the desks immediately and wait until the teacher tells them it is safe to come out. The teacher should, at the same time, go immediately to the teacher's desk, get underneath (在……下面) it and stay there till the danger is over. Students must not argue with the teacher or question instructions. As soon as the tremors (震动) stop, all students should walk towards the exit and go straight to the school playground or any open space such as a square or a park. They must wait there until the teacher tells them it is safe to go. At home If you are at home when the earthquake occurs, get immediately under the table in the living room or kitchen. Choose the biggest and strongest table you can find. You must not go anywhere near the window and don't go out onto the balcony (阳台). Once the tremors have stopped, you can come out from under the table but you must leave the building straight away. You should walk down the stairs and should not use the lift—there may be a power cut as a result of the earthquake and you could find yourself trapped inside the lift for hours. In the street If you are in the street when the earthquake takes place, do not stand near buildings, fences or walls—move away as quickly as possible and try to find a large open space to wait in. Standing under trees could also be dangerous.

单选题In 1881 Clara Barton founded the American National Red Cross, an organization whose goal is to relieve human suffering.A. joinedB. defendedC. locatedD. established