A new study says that birds living in big cities sing shorter, faster songs that are higher-pitched than those sung by their brothers in the forests. The researchers think that the birds adjust their songs to allow themselves to be heard over the noises of the city, especially the low traffic noise. To study how urban birds song, Hans Slabbekoorn and Ardie den Bore, biologists at the University of Leiden in Netherlands, travelled around Europe and recorded bird songs in ten major cities and in nearby forests. The species they focused on, the great tit , is widespread across Eurasia and one of the few types of birds that _ in big cities. Singing is crucial for males, which use their songs to attract mates and mark out their territory. The changing songs could play a role in eventually causing the city birds and the forest dwellers to evolve into separate species. The findings could also help explain why usually only a few bird species thrive in cities. By contrast, many more bird species tend to be found in forests and other undeveloped habitats. Studies like this could eventually help researchers predict how urbanization will affect birds, using this knowledge could help urban planners design more pleasant city environments, study co-author Slabbe-koorn said. "You can make a city much more livable if you pay attention to where the noise goes and where the people go," he said. "It would be easy to fit the birds into those models." Then cities wouldn't be strictly for the people, but also for the birds. What is NOT the effect that studies of birds' songs have? A) Predicting how course of the city's expanding will affect birds. B) Helping the city planners design more pleasant city environments. C) Making cities more livable for both the birds and people. D) Driving the urban birds back to the forest.
D
Recently a study, led by Pedro Hallal of the Federal University, suggests that nearly a third of adults, 31%, are not getting enough exercise. That rates of exercise have declined is hardly a new discovery. Since the beginning of the industrial revolution, technology and economic growth have helped to create a world in which taking exercise is more and more an option rather than a necessity. But only recently have enough good data been collected from enough places to carry out the sort of analysis Dr Hallal and his colleagues have engaged in. There are common themes in different places. Unsurprisingly, people in rich countries are less active than those in poor ones, and old people are less active than young ones. Less obviously, women tend to exercise less than men--34% are inactive, compared with 28% of men. But there are exceptions. The women of Croatia, Finland, Iraq and Luxembourg, for example, move more than their male countrymen. Malta wins the race for most _ country, with 72% of adults getting too little exercise, and Swaziland and Saudi Arabia are in close behind, with 69%. In Bangladesh, just 5% of adults fail to exercise enough. Surprisingly, six Americans in ten are active enough according to Dr Hallal's study, compared with fewer than four in ten British. These high rates of inactivity are worrying. Human beings seem to have evolved to benefit from exercise while deliberately avoiding it whenever they can. In a state of nature it would be impossible to live a life that did not provide enough of it. But that is no longer the case. Actually lack of enough activity these days has nearly the same effect on life span as smoking. What can be the best title for the text? A) Worldwide Lack of Enough Exercise B) New Health Discovery C) Evolvement of Human Beings D) Benefits of Taking Exercise
A
Q: Childhood was an illusion and the illusion was this: everything was bigger. No, I mean everything, not just houses and shops and grown-ups, but colors and flowers and journeys, especially journeys which seemed endless. "Are we there yet, Daddy?" Funfairs were huge things that spread for miles around you with noise and lights and exciting danger. Rainy days at home when you were ill seemed to last for ever. Being a grown-up yourself was an unthinkable distant possibility. Every sound was louder, every game was grander, every pain unbearable. As I've grown old, life has become smaller. Tastes have dulled. Surprises have turned into shocks. Days go by unnoticed. How can I regain childhood when it was an illusion? I have only one repeatable and wonderful way and even in this way I can regain only part of that larger world. I can play upon the stage like a child and make the crowd laugh and laugh with them, sometimes helplessly like a child, and then, even though I'm a sixty-one-year-old man, I can almost catch the colors and sounds and stillness of those bigger years when I was little. The author enjoys playing on the stage so as to _ . A) act like a child B) live an unusual life C) make the crowd laugh D) regain his childhood
A: D
(Q).
My friend Alice decided to be a nurse when she was four years old. She always to play at "doctors and nurses" with her playmates. When she left school last year, she still wanted to be a real nurse. Late September she started her studies in a big hospital in Newcastle. She had to work very hard. She went to classes every day and studied late at night. Then a really important day came: her first day in a ward . At last she was really helping sick people, not just sitting in classes or learning from books. At first, student nurses do lots of odd jobs in the ward. They help to serve meals, or wash the patients. They also keep the ward tidy and make the beds. But they cannot give injections or help the doctors. One of Alice's first jobs was in a ward of old people. She was told to clean all the patients' false teeth. She collected all the teeth and took them to the bathroom. Instead of cleaning each set of teeth one by one, she put them all into a big bowl. "It'll be quicker this way," she said to herself. "Then I can give back everyone's teeth in a few minutes." Give back everyone's teeth! Alice stood in the middle of the ward with her big bowl of teeth. She had no idea which teeth belonged to which old man! You can imagine the confusion of the next half-hour when each patient came to find his own teeth! Alice made up her mind to be a nurse _ . A) when she was just a little child B) when she was at school four years ago C) after she was at school four years ago D) when she began to study in a big hospital
(A).
A