C

     There is an English saying: "Laughter is the best medicine." Until recently, few people took the saying seriously. Now, however, doctors have begun to investigate laughter and the effects it has on the human body. They have found that laughter really can improve people's health.

     Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their heart rate, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise.  It increases blood pressure, the heart rate and breathing. It also works several groups of muscle in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial.

     Other tests have shown that laughter appears to be able to reduce the effects of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group that tolerated pain for the longest time was the one that listened to a funny program. The reason why laughter can reduce pain seems to be that it helps to produce a kind of natural chemical in the brain which decreases both stress and pain.

      As a result of these discoveries, some doctors in the United States now hold laughter clinics, in which they help to improve their patients' condition by encouraging them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

A

    For thousands of years, man has enjoyed the taste of apples. Apples, which are about 85 percent water, grow almost everywhere in the world, both the hottest and coldest areas. Among the leading countries in apple production are China, France and the United States.

     There are various kinds of apples, but a very few make up the majority of those grown for sale. The three most common kinds grown in the United States are Delicious, Golden Deli­cious, and McIntosh.

     Apples are different in colour, size and taste. The colour of the skin may be red, green, or yellow. They have various sizes, with Delicious apples being among the largest. The taste may be sweet or tart (酸的). Generally, sweet apples are eaten fresh while tart apples are used to make applesauce(苹果酱).

      Apple trees may grow as tall as twelve meters. They do best in areas that have very cold winters. Although no fruit is produced during the winter, this cold period is good for the tree.

B

     The year is 2094. It has been announced that a comet (彗星) is heading towards the Earth. Most of it will miss our planet, but two pieces will probably hit the southern half of the Earth.

     On 17 July, a piece four kilometers wide enters the Earth's atmosphere with a massive explosion.  About half of the piece is destroyed, but the remaining part hits the South Atlantic at 200 times the speed of sound. The sea boils and a huge hole is made in the sea bed. Huge waves are created and spread outwards from the hole. The wall of water, a kilometer high, rushes towards southern Africa at 800 kilometers an hour. Cities on the African coast are totally destroyed and millions of people are drowned.

     Before the waves reach South America, the second piece of the comet lands in Argentina.  Earthquakes and volcanoes are set off in the Andes Mountains. The shock waves move north into California and all around the Pacific Ocean. The cities of Los Angeles, San Francisco and Tokyo are completely destroyed by earthquakes. Millions of people in the southern half of the earth are already dead, but the north won’t escape for long.  Because of the explosions, the sun is hidden by clouds of dust, temperatures around the world fall to almost zero. Crops are ruined. The sun won't be seen again for many years. Wars break out as countries fight for food. A year later, no more than 10 million people remain alive.

Could it really happen? Will we meet the same end?

Fear may be felt in the heart as well as in the head, according to a study that has found a link between the cycles of a beating heart and the chance of someone feeling fear.

Tests on healthy volunteers found that they were more likely to feel a sense of fear at the moment when their hearts are contracting（收缩）and pumping blood around their bodies, compared with the point when the heartbeat is relaxed. Scientists say the results suggest that the heart is able to influence how the brain responds to a fearful event, depending on which point it is at in its regular cycle of contraction and relaxation.

Sarah Garfinkel at the Brighton and Sussex Medical School said: “Our study shows for the first time that the way in which we deal with fear is different depending on when we see fearful pictures in relation to our heart.”

The study tested 20 healthy volunteers on their reactions to fear as they were shown pictures of fearful faces. Dr Garfinkel said, “The study showed that fearful faces are better noticed when the heart is pumping than when it is relaxed. Thus our hearts can also affect what we see and what we don’t see and guide whether we see fear.”

To further understand this relationship, the scientists also used a brain scanner（扫描仪）to show how the brain influences the way the heart changes a person’s feeling of fear.

“We have found an important mechanism by which the heart and brain ‘speak’ to each other to change our feelings and reduce fear,” Dr Garfinkel said.

“We hope that by increasing our understanding about how fear is dealt with and ways that it could be reduced, we may be able to develop more successful treatments for anxiety disorders, and also for those who may be suffering from serious stress disorder.”

Did you ever look up at the moon and think you saw a man’s face there? When the moon is round and full, the shadows(影子) of the moon mountains and the lines of the moon valleys sometimes seem to show a giant nose and mouth and eyes. At least, some people think so.

　　If there were a man on the moon—instead of mountains and valleys that just look like the face of a man—what would he be like?

　　He would not be like anyone you know. He would not be like anyone anybody knows.

　　If the man on the moon were bothered by too much heat or cold the way Earth people are, he could not stay on the moon.

　　The moon becomes very, very hot. It becomes as hot as boiling water. And the moon becomes very, very cold. It becomes colder than ice.

　　Whatever part of the moon the sun shines on is hot and bright. The rest of the moon is cold and dark.

　　If the man on the moon had to breathe to stay alive, he couldn’t live on the moon because there’s no air there. He’d have to carry an oxygen tank, as astronauts do. There’s no food on the moon, either. Nothing grows—not even weeds（grass）.

　　If the man on the moon liked to climb mountains, he would be very happy. There are many high places there, such as the raised land around the holes, or craters(火山口), of the moon. Some of these rims are as tall as Earth’s highest mountains.

　　But if the man on the moon liked to swim, he would be unhappy. There is no water on the moon—just dust and rock.

　　When you think of what it’s like on the moon, you may wonder why it interests our scientists. One reason is that the moon is Earth’s nearest neighbor—it is the easiest place in space to get to.

　　Going back and forth between the moon and Earth, astronauts will get a lot of practice in space travel. Things learned on moon trips will be of great help to astronauts who later take long, long trips to some of the planets.

　　Scientists are also interested in the moon because it has no air. The air that surrounds Earth cuts down the view of the scientists who look at the stars through telescopes. A telescope on the moon would give them a clearer, closer view of the stars.

D

People born in winter are more likely to suffer mental health disorders, according to a recent study carried out by researchers at Vanderbilt University in Tennessee.
Researchers raised baby mice from birth to weaning (断奶) in either “summer” light cycles of 16 hours of light and 8 hours of dark or “winter” cycles of 8 hours of light and 16 hours of dark. A third group experienced 12 hours of light and 12 hours of dark a day.
Then half the winter mice stayed in a winter cycle, while half switched to a summer schedule. The summer mice were similarly split. The mice raised in equal periods of light and dark were split into three groups, one of which stayed on the 12­hour schedule, one of which joined the winter group, and one of which joined the summer group.
After 28 days, it turns out the summer­born mice behaved the same whether they stayed on the summer cycle or switched to winter. But among the winter­born mice, those stayed in winter kept their previous schedule, while those that switched to summer stayed active for an extra hour and a half, which indicates that mice born and weaned in a winter light cycle showed dramatic disruptions in their biological clocks.
The finding is the first of its kind in mammals, and it could explain why people born in winter are at higher risk for mental health disorders including bipolar depression, schizophrenia and seasonal affective disorder.
“We know that the biological clock regulates mood in humans，”said study researcher McMahon. “If the mechanism (机制) similar to the one that we found in mice operates in humans, then it could not only have an effect on a number of behavioral disorders, but also have a more general effect on personality.”

(C)

      What will man be like in the future—in 5000 or even 50,000 years from now? We can only make guesses, of course, but we can be sure that he will be different from what he is today, for man is slowly changing all the time.

　　Let us take an obvious example. Man, even five hundred years ago, was shorter than he is today. Now, on average, men are about three inches taller. Five hundred years is relatively short period of time, so we may assume that man will continue to grow taller. Again, in the modern world we use our brains a great deal. Even so, we still make use of only about 20% of the brain’s capacity. As time goes on, however, we shall have to use our brains more and more, and eventually we shall need larger ones! This is likely to bring about a physical change to the head, in particular the forehead, will grow larger.

　　Nowadays our eyes are in constant use. In fact, we use them so much that very often they become weaker and we have to wear glasses. But over very long period of time it is likely that man’s eyes will grow stronger.

　　On the other hand, we tend to make less use of our arms and legs. These, as a result, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive because they are used a great deal in modern life.

　　But what about hair? This will probably disappear from the body altogether in course of time because it does not serve a useful purpose any longer. In the future, then, both sexes are likely to be bald.

　　Perhaps all this gives the impression that future man will not be a very attractive creature to look at! This may well be true. All the same, in spite of all these changes, future man will still have a lot in common with us. He will still be a human being, with thoughts and emotions similar to our own.

Everyone needs water and a diet  (1)  healthy foods. These foods should  (2)  some fat, some fiber, a little salt and so on.

   People need energy to live. They eat all kinds of foods   (3)   change into energy. Our bodies use different  (4)  of energy. The energy is measured in calories(卡路里). The more  (5)  we take, the more calories we burn.  Even when you are  (6)  , you are using energy---about 65 calories an hour. While you are at school, or walking home, your body is  (7)  up 100 calories an hour. When playing football or basketball, you might be using 400 calories an hour. On   (8)  Day, during the relay race, you will use most of all, perhaps as   (9)  as 650 calories an hour.

   The Chinese diet is considered to be the healthiest in the world.  It contains a lot of fruit and green vegetables. It is  (10)  in fiber and low in sugar and fat. The Chinese eat less sugar than many   (11)  countries in the world. That is  (12)  lots of people in China have white teeth.

   People in the Western world do not eat  (13)  healthy foods. They eat too much fat and sugar and don’t take  (14)  exercise. Because of this, they  (15)  very easily. In order to  (16)   with the quick pace(步伐) of their life and work, they eat a lot of fast food. They eat a lot of sweets, soft drinks, potato crisps, chocolate, butter and ice cream and so on,  (17)  are called  (18)  food by some epicureans（美食家）. The result is that many of them become fat. In order to avoid  (19)   fat and  (20)  ​ it is advisable(明智的) to eat a balanced diet and not eat too many foods that have a high calorie rating.

C

The World Health Organization(WHO) said that processed meat be carcinogenic(致癌). Do you still dare eat cancer-linked processed(加工过的) meat? Here are some comments on the website.

    Bill (Australia) I’d rather live a short, pleasant life than a long, unhappy one, denying(拒绝给予) myself tasty food just because some experts say it’s not healthy. We should all enjoy the one life we have—if I had listened to every piece of health advice I would never go anywhere, eat anything or enjoy life in any way. So, I won’t change my habit. I am going to have a bacon sandwich, glass of wine, burger, can of coke whenever I feel like it.

Tim (America) Is meat really as bad as smoking? I don’t think so. According to the WHO 34,000 people die worldwide per year because they eat processed meat. In 2012, 8.2 million people died of cancer worldwide. That means if you eat a lot of processed meat you have a chance of being among the 0.41 percent of people dying of cancer because of processed meat. I’ll take the chance.

Helen (Switzerland) The WHO doesn’t say that just one bite of meat causes cancer, it is rather saying that people should vary their diet. People who eat more meat often have other unhealthy habits. They usually eat fewer fruits and vegetables and they also often exercise less.

Van (China) Perhaps this report will make people consider becoming vegetarians(素食者). So for your health, the environment and future generations, it is not difficult; it just needs a change of attitude. There is a vast variety of other delicious food available to enjoy.