3 . Most young people enjoy some form of physical activity. It may be walking, cycling, or swimming, or in winter, skating or skiing.     1     It may be mountaineering.

Those who have a passion for climbing high and difficult mountains are often looked upon with astonishment.

Why are men and women willing to suffer cold and hardship, and to take risks on high mountains? This astonishment is caused probably by the difference between mountaineering and other forms of activity from which men get their relaxation.

Mountaineering is a sport but not a game. There are no man-made rules, as there are for such games as golf and football. There are, of course, rules of a different kind which it would be dangerous to ignore, but it is this freedom from man-made rules that makes mountaineering attractive to many people.     2    

If we compare mountaineering with other more familiar sports, we might think that one big difference is that mountaineering is not a “team game”.     3     There are, it is true, no “matches” between “teams" of climbers, but when climbers are on a rock face linked by a rope on which their lives may depend, there is obviously teamwork.

The mountain climber knows that he may have to fight forces that are stronger and more powerful than man.     4     His sport requires high mental and physical qualities.

A mountain climber continues to improve skills year after year. A skier is probably past his best by the age of thirty, and most international tennis champions are in their early twenties.     5     They may need more time than younger men, but they probably climb with more skills and less waste of effort, and they certainly experience equal enjoyment.

A．We should be mistaken in this.

B．He has to fight the forces of nature.

C．Teams compete against each other.

D．Climbing high mountains needs patience, skills and strength.

E．Those who climb mountains are free to use their own methods.

F．It may be a game of some kind football, hockey, golf, or tennis.

G．But it is not unusual for men of fifty or sixty to climb the highest mountains in the Alps.

4 . Exercise could not only benefit your body, but also improve your memory, researchers found recently. In their paper published on Monday, researchers from the University of California, Irvine in the United States and the University of Tsukuba in Japan introduced their experiment and conclusion.

Scientists invited 36 volunteers who were in their early 20s to do 10 minutes of light exercise before taking a memory test in which they were shown pictures like broccoli（西兰花）or picnic baskets and asked to recall them later. The same experiment was repeated with the same group of volunteers without exercising. ^u The memory task was really quite challenging , "   said Michael Yassa,co-author of the study and a neuroscientist （神经科学家）at the University of California, Irvine. "We used very tricky similar items to see if they would remember whether it was this exact picnic basket versus （对抗）that picnic basket. "

Researchers also scanned brains of some, of the participants during the experiment. They found strengthened communication between regions involved in the storage and recollection of memories in brains of those who had exercised. This suggested that just 10 minutes of light exercise like walking,yoga or Tai Chi might increase memory power.

As all the volunteers in the experiment were relatively young, researchers are still working to look at the effects of light exercise on older people. "Our future goal is to try to develop an exercise prescription（处方） that can be used by older adults who might have disabilities or mobility impairments,but can still adopt very simple exercise rules of life and be able to,perhaps,delay cognitive decline temporarily," said Yassa.

1. What did the researchers find from the experiment mentioned in the text?

A．Regular exercise is of benefit to the memory of all people.

B．Just a short period of exercise better young people's memory power.

C．Older people can also improve their cognitive power by exercising regularly.

D．All the volunteers in the experiment improved their memory through exercise.

2. Why was the memory task quite challenging?

A．The time to solve the questions was too limited.

B．The people in the experiment were disabled.

C．The items to be distinguished were extremely similar.

D．The questions asked by the scientists were too complicated.

3. What's the purpose of the text?

A．.To solve a problem.	B．To give practical advice.
C．To present a research result.	D．To tell an interesting story.

4. What can be a suitable title for the text?

A．Advantages of Exercising Regularly

B．Exercise Is Beneficial to Both Young and Old

C．Exercise Can Improve Older People's Cognitive Power

D．Ten Minutes of Exercise a Day Might Improve Memory