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

Jumping off random cliffs(悬崖) into the sea is not clever. However, as a sport, coasteering uses local experts to help groups travel around the coast so they can then jump safely and have a lot of fun in the process. But coasteering is also so much more than cliff jumping.

A usual day’s coasteering will involve swimming, climbing, scrambling(攀岩) and cliff jumping. All trips begin with a safety brief and equipment check. You will be equipped with a helmet, wetsuit and life vest. You will need to wear some old sneakers you don’t mind getting wet.

From here it could be a short swim to the first jump site. Following an instructor, you swim through rock pools, around rough rocks and right up to the next jump spot. A brief climb and you’ll be standing on the edge wondering, “Why the hell did I agree to this?” Then, and to the yell of your friends, you’re leaping in, with a smile that’s guaranteed to last the rest of the day.

Coasteering is certainly more than cliff jumping. If ever a sport could claim to be confidence building, this is it. And it’s also a perfect activity for groups of friends or for adventurous families who want to explore the coast. Many companies offer daily trips, so even if you are on your own or a couple you can join in with a large group. Companies use trained guides with much knowledge of local tides and weather conditions. These people lead the show and are qualified lifesavers as well.

Coasteering is already popular around the UK. At least now you won’t have to ask “What is coasteering?” if someone you know gives it a go.

1.What is coasteering?

A. A daily sightseeing trip.

B. A non-expert guided diving.

C. A cliff and water based sport.

D. A group activity of climbing.

2.What is the benefit of coasteering?

A. Building confidence.

B. Developing independence.

C. Improving guiding skills.

D. Enriching lifesaving experience.

3.What can we infer from the underlined sentence in Paragraph 3?

A. You felt scared and regretful.

B. You became totally tired.

C. You discovered your potential.

D. You gained complete relief.

4.What is the author’s purpose in writing the text?

A. To introduce coasteering.

B. To organize coasteering.

C. To advertise spots for coasteering.

D. To train coasteering-lovers.

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

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