Commenting on their findings, the researchers say physical activity has been associated with positive emotional well-being, reduced sadness, anxiety and stress disorders, and improved self-esteem（自尊）in teenagers.

　　The researchers note that their study stresses the importance for physicians caring for teenagers to check their level of sports practice and ask them about well-being. Teenagers probably need a supportive and closer follow-up of their health and well-being. The findings can inform guideline groups who produce recommendations on sports practice for teenagers.

25.From the first paragraph we can conclude that _________.

　　A. teenagers negatively do sports

　　B. everything coin has two sides

　　C. active sports does good to health

　　D. lack of exercise influences health

26. What does the underlined word "detrimental" in Paragraph 2 mean?

　　A. Positive. B. Essential. C. Beneficial. D. Harmful.

27. What did the researchers find out?

　　A. Overdoing sport exercise is unhealthy for teenagers.

　　B. Taking part in sport less is the cause of overweight.

　　C. Very high activity groups tend to get higher well-being scores.

　　D. Self-esteem is improved by unlimited sport activity.

28. How do physicians assess teenagers' health from the study?

　　A. The way to promote teenagers' physical health.

　　B. The importance of checking their level of workout.

　　C. The method of improving their emotional well-being.

　　D. The necessity of giving suggestions on their workout.

　　　　　　　　　　　　　　　　　　C

　　Every year thousands of tourists visit Pompeii, Italy. They see the sights that Pompeii is famous for---its stadium and theaters, its shops and restaurants. The tourists do not, however, see Pompeii's people. They do not see them because Pompeii has no people. No one has lived in Pompeii for almost 2,000 years.

　　Once, Pompeii was a busy city of 22,000 people. It lay at the foot of Mount Vesuvius, a grass-covered volcano. Mount Vesuvius had not erupted for centuries, so the people of Pompeii felt safe. But they were not.

　　In August of AD 79, Mount Vesuvius erupted. The entire top of the mountain exploded, and a huge black cloud rose into the air. Soon stones and hot ash began to fall on Pompeii. When the eruption ended two days later, Pompeii was buried under 20 feet of stones and ashes. Almost all of its people were dead.

　　For centuries, Pompeii lay buried under stone and ash. Then, in the year 1861, an Italian scientist named Ginseppe began to uncover Pompeii. Slowly, carefully, Ginseppe and his men dug. The city looked almost the same as it had looked in AD 79. There were streets and fountains, houses and shops. There was a stadium with 20,000 seats. Perhaps the most important of all there everyday objects, which tell us a great deal about the people of Pompeii who lived in Pompeii. Many glasses and jars had some dark blue color in the bottom, so we know that the people of Pompeii liked wine. They liked bread, too; metal bread pans were in every bakery. In one bakery there were 81 round, flat loaves of bread---a type of bread that is still sold in Italy today. Tiny boxes filled with a dark, shiny powder tell us that women liked to wear eye-makeup.

Geinseppe has died, but his work continues. One-fourth has not been uncovered yet. Scientists