单项选择题 The Body Clock Why is it that flying to New York from London will leave you feeling less tired than flying to London from New York? The answer may be a clear case of biology not being able to keep up with technology.Deep inside the brain there is a 'clock' that governs every aspect of the body's functioning: sleep and wake cycles, levels of alertness, performance, mood, hormonelevels, digestion, body temperature and so on. It regulates all of these functions on a 24-hour basis and is called the biological clock.This body clock programmes us to be sleepy twice a day, between 3-5 am and again between 3-5 pm. Afternoon tea and nap are all cultural responses to our natural biological sleepiness in the afternoon.One of the major causes of the travellers' malady known as jet lag is the non-alignment of a person's internal body clock with clocks in the external world.Crossing different time zones confuses the biological clock, which then has to adjust to the new time and patterns of light and activity. To make matters more complex, not all internal body functions adjust at the same rate. So your sleep/wake may adjust to a new time zone at one rate, while your temperature adjusts at a different pace. Your digestion may be on a different schedule altogether.Though we live in a 24-hour day, the natural tendency of the body clock is to extend our day beyond 24 hours. It is contrary to our biological programming to 'shrink' our day.That is why traveling in a westward direction is more body-clock friendly than flying east. NASA studies of long haul pilots showed that westward travel was associated with significantly better sleep quantity and quality than eastward flights.When flying west, you are 'extending' your day, thus traveling in the natural direction of your internal clock. Flying eastward will involve 'shrinking'' or reducing your day and is in direct opposition to your internal clock's natural tendency.One of the more common complaints of travelers is that their sleep becomes disrupted．There are many reasons for this: changing time zones and schedules,changing light and activity levels, trying to sleep when your body clock is programmed to be awake, disruption of the internal biological clock and working longer hours.It is often suggested that you adjust your watch as soon as you board a plane,supposedly to try to help you adjust to your destination's schedule as soon as you arrive.But it can take the body clock several days to several weeks to fully adjust to a new time zone.So, our body clock truly can 'govern' us. 第 41 题 The role of the body clock is toA．enable us to sleep 6 hours a day.B．help us adapt to a 24-hour cycle.C．regulate the body's functions.D．interfere with the body's functions.

单项选择题 A Dolphin and an Astronome One day in 1963, a dolphin named Elvar and a famous astronomer, Carl Sagan,were playing a little game. The astronomer was visiting an institute which was looking into the way dolphins communicate with each other. Sagan was standing on the edge of one of the tanks where several of these friendly, highly intelligent creatures were kept. Eivar had just swum up alongside him and had turned on his back.The dolphin wanted Sagan to scratch his stomach again, as the astronomer had done twice before. Elvar looked up at Sagan, waiting.Then,after a minute or so, the dolphin leapt up through the water and made a sound just like the word 'more'. The astonished astronomer went to the director of the institute and told him about the incident 'Oh, yes. That's one of the words he knows,' the director said, showing no Surprise at all.Dolphins have bigger brains in proportion to their body size than humans have, and it has been known for a long time that they can make a number of sounds. What is more,these sounds seem to have different functions, such as warning each other of danger.Sound travels much faster and much further in water than it does in air. That is why the parts of the brain that deal with sound are much better developed in dolphins than in humans, But can it be said that dolphins have a 'language', in the real sense of the word?Scientists don't agree on this.A language is not just a collection of sounds, or even words. A language has a structure and what we call a grammar. The structure and grammar of a language help to give it meaning. For example, the two questions 'Who loves Mary?' and 'Who does Mary love?' mean very different things. If you stop to think about it, you will see that this difference doesn't come from the words in the question but from the difference in structure. That is why the question 'Can dolphins speak?' can't be answered until we find out if dolphins not only make sounds but also arrange them in a grammatical order which affects their meaning. 第 16 题 The astronomer was not interested in the way dolphins communicate with each other.A．RightB．WrongC．Not mentioned

单项选择题 A． worse B．different C．separatedD．similar