题目内容
Birds in cities are damaging their health by trying to sing above the noise of urban life．
New research shows that male birds are trying to compete against traffic and city sounds．They are now singing louder and at higher frequencies，which could harm their vocal cords(声带)．Some birds are choosing to sing at night instead of during the day．This makes them more open to attack and also creates stress and exhaustion．
“The difference between urban and rural birdsong is becoming so big that the two groups could now be unable to communicate．This could lead to inbreeding(同系交配)and a weak gene poo1．”said Dr Sue Anne Zollinger of the．University of St Andrews．
According to Zollingar，a bird group with a small gene pool might adapt less quickly to new diseases and could be wiped out．
A study of the dawn chorus found that birds in Berlin sang up to 14 decibels(分贝)louder than those in the forest．The birds sang loudest on weekday mornings．
“By trying to sing over the sound of the city，birds ale rising vocal injury，”said Zollinger．“All this puts the same strain on a bird’s vocal cords as when a human need to shout to be heard―except that the birds are doing it all day，every day，”she said．
“Singing under such pressure means birds have less control over the sound they produce．Their songs may lose quality and become more rough―sounding．”said Zollinger．This could make them appear less attractive to female birds．
Mark Constantine，author of The Sound Approach to Birding，said：“Birdsong is important for our quality of life and has been proved to reduce our blood pressure．When we live in the centre of large，urban areas，we get stressed and it’s extremely good to have birdsong around us．The impact on humans of birdsong is massive．It harms us，as well as the birds，if their songs become louder and simpler．
68．Some birds in cities now choose to sing at night time because____________．
A．they want to attract more birds of opposite sex
B．they are more likely to be discovered by their family
C．they can’t adapt to the loud noises during the daytime
D．they have to frighten their enemy away
69．According to the passage，urban and rural birds might not be able to___________．
A．recognize each other
B．communicate with each other
C．1ive with each other
D．compete against each other
70．It requires greatest efforts for birds in cities to sing on______________．
A．Monday nights
B．Wednesday afternoons
C．Saturday Evenings
D．Friday mornings
71．According to Dr Sue Anne Zollinger，birds singing louder might eventually lead to ___________．
A．the harm done to man’s health
B．the dying out of a species
C．the serious damage to the bird’s vocal cords
D．the decrease of the birth rate of a bird group
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红果子三级测试卷系列答案Birds that are half-asleep—with one brain hemisphere (半球) alert and the other sleeping—control which side of the brain remains awake, according to a new study of sleeping ducks.
Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.
Decades of studies of bird groups led researchers to predict extra alertness in the end-of-the-row sleepers which tend to be attacked more easily. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction.
Also, birds napping at the end of the line depend on single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Turning 16 birds through the positions in a four-duck row, the researchers found that compared with 12 percent for birds in internal spots, outer birds half-asleep during some 32 percent of napping time.
“We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness at the same time in different regions of the brain,” the researchers say.
The results provide the best evidence for a long-standing assumption that single-hemisphere sleep evolved as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. He’s seen it in a pair of birds napping side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open.
Useful as half-sleeping might be, it’s only been found in birds and such water animals as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning.
Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds’ half-brain sleep “is just the tip of the iceberg.” He supposes that more examples may turn up when we take a closer look at other species.
【小题1】According to the passage, birds often half sleep because ______.
| A．they have to watch out for possible attacks |
| B．their brain hemispheres take turns to rest |
| C．the two halves of their brain are differently structured |
| D．they have to constantly keep an eye on their companions |
| A．An imagined companion gives the bird a sense of security. |
| B．Birds prefer to sleep in pairs for the sake of their security. |
| C．The phenomenon of birds napping in pairs is widespread. |
| D．A single pet bird enjoys seeing its own reflection in the mirror. |
| A．alert themselves to the approaching enemy |
| B．emerge from water now and then to breathe |
| C．be sensitive to the ever-changing environment |
| D．avoid being swept away by rapid currents |
| A．half-brain sleep has something to do with icy weather |
| B．the mystery of half-brain sleep is close to being solved |
| C．most birds living in cold regions tend to be half sleepers |
| D．half-brain sleep may exist among other species |
Ever since farmers began to grow grain, they have had to protect their crops from birds. In the 1300's, English farmers hired children to protect their crops. They were called “bird scares”. The children chased birds and threw stones at them.
Bird scares were replaced in the 1800's by scarecrows. A scarecrow is anything that is set in a field to scare birds away. Often it is a pole dressed like a person. Some farms with small fields still use scarecrows today.
Farming became big business in the twentieth century. Scarecrows could no longer protect the huge fields of grain, so farmers used poisonous chemicals on the fields. The poison made the grain bitter. The birds usually would not eat the bitter grain.
Although they can prevent crops from being destroyed by insects and birds, some chemicals can be harmful to humans. Therefore, farmers are using fewer chemicals now than they did twenty years ago. Perhaps scarecrows may be seen more often in the fields in the future.
【小题1】English farmers began to hire children to get away birds since_____.
| A．the twelfth century | B．the fifteenth century |
| C．the sixteenth century | D．the fourteenth century |
| A．feeding them bitter grain | B．pretending to be scarecrows |
| C．spreading chemicals in the fields | D．chasing them and throwing stones |
| A．Scarecrows could no longer protect fields. | B．They were called “bird scares”. |
| C．English farmers hired children. | D．Farmers are using fewer chemicals. |
| A．give information about children who worked as bird scares |
| B．tell how crops have been protected from birds |
| C．make the readers feel sorry for birds that eat poisoned grain |
| D．entertain the readers with a funny story |
The famous director of a big and expensive movie planned to film a beautiful sunset over the ocean so that the audiences could see his hero and heroine in front of it at the end of the film as they said goodbye to each other for ever . He sent his camera crew（摄制组）out one evening to film the sunset for him .
The next morning he said to the men , “ Have you provided me with that sunset ? ”
“ No , sir . ” the men answered .
The director was angry . “ Why not ? ” he asked .
“ Well , sir , ” one of the men answered . “ we’re on the east coast here , and the sets in the west . We can get you a sunrise over the sea , if necessary , but not a sunset . ”
“ But I want a sunset ! ” the director shouted . “ Go to the airport . take the next flight to the west coast , and get one . ”
But then a young secretary had an idea . “ Why don’t you photograph a sunrise . ” she suggested . “ and then play it backwards ? Then it’ll look like a sunset . ”
The camera crew went out early the next morning and filmed a bright sunrise over the beach in the middle of a beautiful bay（海湾）. Then at nine o’clock they took it to the director . “ Here it is sir . ” they said , and gave it to him . He was very pleased .
They all went into the studio（摄影棚）. “ All right . ” the director explained . “ now our hero and heroine are going to say good-bye . Run the film backwards so that we can see the ‘ sunset behind them . ’ ”
The “ sunset ” began , but after a quarter of a minute , the director suddenly put his face in his hands and shouted to the camera crew to stop .
The birds in the film were flying backwards . and the waves on the sea were going away from the beach .
【小题1】One evening, the director sent his camera crew out .
| A．to watch a beautiful sunset |
| B．to find an actor and an actress |
| C．to film a sunset scene on the sea |
| D．to meet the audience |
| A．Because he changed his mind about getting a sunset . |
| B．Because he wanted to get a scene of sunset . |
| C．Because it was his secretary’s suggestion . |
| D．Because he was angry with his crew . |
| A．The crew had to follow the secretary’s advice . |
| B．If you want to see a sunrise , the east coast is the place to go to . |
| C．The camera crew wasn’t able to film the scene the first day . |
| D．The director ordered his crew to stop filming the “ sunset ” . |
| A．it went well with the separation of the hero and the heroine |
| B．when they arrived at the beach it was already in the evening |
| C．it was more moving than a sunrise |
| D．the ocean looked more beautiful at sunset |
| A．because he was moved to tears |
| B．as he saw everything in the film moving backwards |
| C．as the sunrise did not look as beautiful as he had imagined |
| D．because he was disappointed with the performance of the hero and heroine |