Exercise may help to safeguard the mind against depression through previously unknown effects on working muscles, according to a new study involving mice.  

Mental health experts have long been aware that even mild, repeated stress can contribute to the development of depression and other mood disorders in animals and people. Scientists have also known that exercise seems to cushion against depression. But precisely how exercise, a physical activity can lessen someone’s risk for depression, a mood state, has been mysterious. So for the new study, researchers at the Karolinska Institute in Stockholm studied the brains and behavior of mice in a complicated and novel fashion.

We can’t ask mice if they are feeling cheerful or in low spirits. Instead, researchers have pictured certain behaviors that indicate depression in mice. If animals lose weight, stop seeking out a sugar solution when it’s available — because, probably, they no longer experience normal pleasures — or give up trying to escape from the cold-water zone just freeze in place, they are categorized as depressed. And in the new experiment, after five weeks of frequent but low-level stress, such as being lightly shocked, mice displayed exactly those behaviors. They became depressed. 

The scientists could then have tested whether exercise blunts (延缓) the risk of developing depression after stress by having mice run first. But, frankly, from earlier research, they wanted to know how, so they bred pre-exercised mice. A wealth of earlier research by these scientists and others had shown that aerobic exercise, in both mice and people, increases the production within muscles of an enzyme (酶) called PGC-1alpha. The Karolinska scientists suspected that this enzyme somehow creates conditions within the body that protect the brain against depression. Then, the scientists exposed the animals, which without exercising, were in high levels of PGC-1alpha to five weeks of mild stress. The mice responded with slight symptoms of worry. But they did not develop depression. They continued to seek out sugar and fought to get out of the cold-water zone. Their high levels of PGC-1alpha appeared to make them depression-resistant. Finally, to ensure that these findings are relevant to people, the researchers had a group of adult volunteers complete three weeks of frequent endurance training, consisting of 40 to 50 minutes of moderate cycling or jogging. The scientists conducted muscle biopsies (活体检查) before and after the program and found that by the end of the three weeks, the volunteers’ muscle cells contained substantially more PGC-1alpha than at the study’s start. The finding of these results, in the simplest terms, is that “you reduce the risk of getting depression when you exercise,” said Maria Lindskog, a researcher at the Karolinska Institute.

1.The researchers at the Karolinska Institute in Stockholm conducted the new study hoping to know______.

A. if exercise cushions against depression

B. what can lead to depression in animals and people

C. if stress can contribute to the development of depression

D. how exercise contributes to reducing someone’s risk for depression

2.We can infer from the new experiment conducted by researchers at the Karolinska Institute that mice are depressed except when ______.

A. they stand still in place

B. they stop searching for the sugar water

C. they attempt to escape from the cold-water zone

D. they can’t experience normal pleasures any longer

3.Researchers asked a group of adult volunteers to complete three weeks of frequent endurance training in order to ______.

A. know if exercise can help to safeguard the mind against depression

B. know if they can endure 40 to 50 minutes of moderate cycling or jogging

C. confirm the findings above are also relevant to people

D. ensure they can lose weight after moderate cycling or jogging

4.It can be concluded from the passage that______.

A. the enzyme called PGC-1alpha helps to ease depression

B. athletes are more likely to develop depression than ordinary people

C. the mice with high levels of PGC-1alpha are easier to develop depression

D. in the past mental health specialists didn’t know exercise could help reduce depression

What should you think about when trying to find your career?You are probably better at some school subjects than others.These may show the strengths that you can use in your work.A boy who is good at mathematics can use that in an engineering career. A girl who spells well and likes English may be good at office work.So it is important to know the subjects you do well in at school.On the other hand,you may not have any specially strong subjects but your records show a general satisfactory standard.Although not all subjects can be used directly in a job,they may have indirect value.A knowledge of history is not required for most jobs but if history is one of your good subjects you will have learned to remember facts and details.This is an ability that can be useful in many jobs.

Your school may have taught you skills,such as typing or technical drawing,which you can use in your work.You may be good at metalwork or cookery and look for a job where you can improve these skills.If you have had a part?time job on Saturdays or in the summer,think what you gained from it.If nothing else,you may have learned how to get to work on time,to follow instructions and to get on with older workers.You may have learned to give correct change in a shop,for example.Just as important,you may become interested in a particular industry or career you see from the inside in a part?time job.

Facing your weak points is also part of knowing yourself.You may be_ all_ thumbs when you handle tools;perhaps you are a poor speller or cannot add up a column of figures.It is better to face any weakness than to pretend they do not exist.Your school record,for instance,may not be too good,yet it is an important part of your background. You should not be apologetic(认错的)about it but instead recognize that you will have a chance of a fresh start at work.

1.What is the passage mainly about?

A. The importance of working hard at school.

B. Choosing a career according to one's strengths.

C. How to face one's weakness.

D. The value of school work.

2.According to the passage,doing a part?time job for a student is probably ______.

A. a good way to find out his weak points

B. one of the best ways of earning extra money

C. of great use for his work in the future

D. a waste of time he could have spent on study

3.The underlined phrase “be all thumbs”(in Para.3)probably means “______”.

A. be clumsy at doing things B. be skillful in doing things

C. be not interested in certain things D. be easily bored in doing things

4.From the last paragraph we know one should ______.

A. make full use of one's own weak points B. study harder for a new school record

C. apologize for one's own school record D. face one's own weak points bravely

Recently, I went to a small town for a short holiday with my husband and daughter. On the first evening, we decided to visit the nearest ______ to check out the local foods and do s0me shopping as well. After spending some time ______ this and that, we decided to get a bite to eat. We had to ______ our turn at the restaurant. I stood on the ______ outside, looking at the crowd of ______ makers.

____, I noticed a small boy of about seven carrying several hand-made gift ______. They were small but very ______. The boy asked me to buy one, ______ widely. He said he had ______ the bags himself as he wanted to help ______ the family. I smiled back and asked the ______ of the bags. He named a(n) ______. I told him it was too ______ for such small bag.

The boy ______ that he had to buy paper and string(线)which ______ him a lot. At that time, I was still hesitating(犹豫), ______ he smiled another sweet smile saying, “Miss, please ______ one, I really worked hard to make it day and night.” His smile stole my ______ and bought a red bag. The boy left ______ the cash carefully in his pocket, but with another of his smile. That day I knew I had met God.

1.A. restaurants B. hospitals C. factories D. schools

2.A. saying B. performing C. buying D. protecting

3.A. break up B. stand for C. pick up D. wait for

4.A. table B. street C. roof D. window

5.A. paper B. voyage C. holiday D. loss

6.A. Hopelessly B. Confidently C. Independently D. Suddenly

7.A. bags B. signals C. books D. toys

8.A. dirty B. Colorful C. ugly D. thin

9.A. smiling B. thinking C. agreeing D. looking

10.A. borrowed B. invented C. made D. inspected

11.A. admire B. move C. feed D. visit

12.A. color B. size C. quality D. price

13.A. number B. invitation C. secret D. plan

14.A. little B. young C. much D. short

15.A. guessed B. hoped C. explained D. decided

16.A. cost B. paid C. appreciated D. saved

17.A. or B. so C. if D. because

18.A. stop B. remember C. take D. sell

19.A. pain B. heart C. bag D. car

20.A. removing B. spending C. wasting D. storing

An artist in Bogota, Colombia is using his skills to aid the homeless. Greg Kloehn builds very small shelters that make life on the streets a little more comfortable. The structures offer the homeless some safety and protection from bad weather. Each little house also has wheels on the bottom so it can go wherever its owner goes.

Greg Kloehn has given away at least 20 tiny houses. Several are on the roadside near an active railroad. On a recent day, Mr. Kloehn stops at one to visit Oscar Young. The two men hug. Inside his little shelter Mr. Young gets relief from cold nights on the streets. Mr. Kloehn also visits Sweet-Pea, another friend who also lives in one of the little homes the artist built. She says it keeps her safe and protects her belongings.

In the mornings, Mr. Kloehn searches the streets for building materials. He gathers what he can and takes it to his studio. There, he puts the houses together. Empty coffee bags become roof material. A washing machine door and refrigerator part become windows. Nails, screws and the sticky glue hold all the pieces together. The artist also attaches a small electrical device to the house. The device is powered by the sun.

Some of the people living on the streets once had normal houses of their own. But some of the people say they have learned to live with the homeless and they are thankful to that man.

Mr. Kloehn says his work is not a social project. He says he is just someone applying his skills to helping his homeless neighbors.

1.The following are the advantages of the small shelters except ________.

A. saving power and energy

B. protecting possessions of the homeless

C. decorating the streets where they are

D. keeping the homeless safe and comfortable

2.We can learn from the passage that ________.

A. Greg Kloehn has sold at least 20 tiny houses

B. an act of kindness has made people simple and grateful

C. The shelters are immovable

D. The government has got involved in the action

3.The passage is likely taken from ________.

A. an official report B. an art review

C. a fictional brochure D. a news report

4.What’s the main idea of the passage?

A. An artist creates homes for the homeless.

B. A more comfortable shelter on the streets.

C. A successful social project in Bogota.

D. An artist makes a living by designing small shelters.

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