4 . During the last twenty years there has been increasing concern with the quality of the environment. Along with air and water pollutants, noise pollution has been considered as a serious pollutant. As noise levels have risen, the effects of noise have become more obvious.

Noise is described as “unwanted sound”. Causes of noise pollution include traffic, aircraft, rock bands, barking dogs, television, garbage trucks, and noise from neighbors, voices, alarms, and boats. Studies show that over forty percent of Americans are disturbed at home or lose sleep because of noise pollution.

Noise has bad effects on people and the environment. Noise causes hearing loss, interferes (干扰) with human activities at home and work, and is in various ways dangerous to people’s health and well-being.

When we think, talk, listen to music, or sleep, we need quiet. Even low levels of noise can be annoying or frustrating. Sudden increases in volume can make sounds annoying. The quieter the background is, the more penetrating a noise can be.

Noise can also make instructions or warning unclear, resulting in accidents. Louder noise bursts can cause more problems. Continued stress caused by living in noisy conditions can lead to high blood pressure, which is the major cause of some diseases.

Long exposure to noise levels above eighty-five decibels (分贝) can damage inner ear cells and lead to hearing loss. Noise can result in the uncontrolled fear response and can cause adrenaline (肾上腺素) to be pumped into the bloodstream, the heart rate to quicken, muscles to tense, breathing to go up, and the digestive system to slow down.

Local government has the responsibility to fight noise pollution. For example, it can regulate the speed of trains through their community. On the other hand, a responsible citizen will never make noise pollution wherever he is.

Are People Unique?

A considerable number of people consider other species on earth are somehow inferior to us. Throughout the history, it has always been human beings’ pride    1     we are the only species on the Planet that can speak and think. However, recent research casts doubt on that common belief.

Zuberbuhler, a psychologist at St. Andrews University, and his colleagues recorded thousands of calls made by Diana’s monkeys and noticed that the monkeys adapted their calls to change the meaning    2    (warn) one another about different situations. For example, they made a krack alarm call at the sight of tiger. However, when they merely repeated calls made by other monkeys they added an “oo”.

The researchers found that the same calls     3    (recognize) by other species, like Campbell’s monkeys.“So they are communicating across species. And since then we have found that hornbill birds can understand these calls and they too can understand all the different meanings.” said Zuberbuhler.

    4     is also surprising is that signs of intelligence have been found in birds,     5     small brains were long assumed to be a complete barrier to intelligence. However, all that is changing fast. A few years ago Irene Pepperberg of the Massachusetts Institute of Technology taught a parrot to recognize and count up to six objects,     6    couldn’t have been achieved if birds were unable to memorize things.

Last year, that was topped by Alex Kacelnik, a professor of behavioral ecology at Oxford, who discovered that crows (G49) are capable of using tools on complex orders. This was the first time that such behaviour     7     (observe) in non-humans. In an experiment seven crows successfully grabbed a piece of food     8     (place) out of reach using three different lengths of stick. Crucially, they were able to complete the task without any special training,     9    (suggest) the birds were capable of a level of abstract reasoning normally associated only with humans.

All this is powerful evidence     10    the idea that people are unique.

9 . Do you know one bird whose name is crow (乌鸦)?Here is a story about one of them. There was once a lazy crow who thought it was too much trouble to _________ food. “Caw! Caw!” he said “If someone brought me my food every day, I’d be very _________!”

One day he saw a(n) _________ pigeon flying by. “How happy and well-fed it looks ” the crow said to himself. So the crow _________ the pigeon until they came to a _________. There were some other _________ there too. Before long an old man came along and brought them a large bag of food. When the man had gone ,the crow flew over to the pigeons. “Caw!Caw!” said he. “Can I _________ you?”

“No, you can’t!” _________ the pigeons angrily. “We don’t know you.”

The crow went home feeling _________. But he suddenly had a(n) __________. “I’ll paint my __________ grey,” he said, “and then the pigeons will __________ I am one of them.” After he finished the painting, he flew off to the park and was __________ by the pigeons. The crow was so hungry that he got very excited at the food. “Caw! Caw! Give food to me!” he said loudly. __________ the pigeons found he was a crow. They flew after him and made him __________.

Sadly the crow flew to his own forest. But when his old friends, the other crows saw him they asked him to __________. They did not __________ him because of his grey-painted feathers. So the crow felt __________ than before. His own __________ did not want him, __________ the pigeons wouldn’t let him into their group.

“What looks easier isn’t always so,” the crow said to himself. “I wish I had never painted my feathers grey!”

10 . The Arctic will soon be free from ice, experts say. The change is bound (必定的) to take place, but the global warming and climate change are changing the earth’ s landscape (地形) rapidly, causing panic worldwide.

Experts say that the Arctic sea ice is melting (融化) quite faster than expected and it can affect not just the region, but Earth in general. A scientist even says that next year, or maybe the year after that, the Arctic will be free of ice.

Peter Wadhams, a scientist, said that the melting trend led to his statement. “Most people expect this year will see a record low in the Arctic’s summer sea-ice cover. Next year or the year after that, I think it will be free of ice in summer and by that I mean the central Arctic will be ice-free,” Peter Wadhams, director of the Scott Polar Institute in Cambridge, said in an interview with the Guardian. “You will be able to cross over the North Pole by ship,” Peter Wadhams added. He strongly believes that although some pieces of ice will remain, the Arctic basin may be free of sea ice in the next two years starting in the summer of 2017.

Wadhams’ study says that melting sea ice will have a great influence on the planet since the sea ice is more able to reflect (反射) sunlight compared to water that can only reflect 10% of the sunlight. Once the sea ice melts, the water can only reflect a small amount of sunlight. This means that the Earth will receive and absorb more sunlight, making the planet even hotter.

The year 2016 has already broken records of the hottest temperature ever recorded and the trend doesn’t seem to show any decrease in global warming. “It doesn’t look like the ice is healing and growing back,” Tom Wagner, NASA’ s manager for cryosphere (冰冻圈) research said in a statement.

Like Wadhams, scientists and researchers all over the world are lecturing around to educate people to help lighten global warming that has already changed the planet’s landscape.