题目内容：

Many people take running as a way to keep fit. They like to run in hot weather and enjoy the feeling of being wet through with sweat while running. Cold weather during winter months, with low temperatures and freezing cold winds, may keep many people from running in the open air.

However, a new study shows that the drop in temperature is a good reason to run. In fact, running in cold weather helps improve one’s performance. Many runners might find it easier to run in winter than in hot weather.

Lower temperatures reduce stress on the body. When you run in cold weather, your heart rate is lower. And the body needs less water on a cold day than in warm weather because dehydration levels are lower in winter than in warmer conditions.

John Brewer is a professor of applied sports science at ST. Mary’s University in London. For this study, he and other researchers put a group of people into a room where summer and winter weather conditions are recreated. The test subjects, were asked to run 10,000 meters under both conditions and their biological measurements were recorded and studied.

From the study, every movement runners make produces heat. The heat can be really damaging unless the body can lose it. One way in which people lose heat is by sweating. The body loses heat through droplets of sweet. The body also loses it by transporting the blood to the surface of the skin and it puts more stress on the heart, particularly in hot conditions because it’s much harder to lose heat when the outside environment is warm. As the result shows running in hot temperatures results in 6 percent higher heart rates. 

When running in cold conditions, the body does not have to work hard to pump blood to the skin surface. Therefore, it requires less energy. The most important thing for people who run in cold conditions is to wear the right clothing. Keep as dry as possible when exercising in low temperatures. Wear mittens on your hands instead of gloves. Wear more than one layer of clothing to keep sweat away from your skin. So don’t let winter weather keep you indoors. Simply get ready for the low temperatures and start running.

1.Why do most people dislike running outdoors in winter?

A. It’s too cold.    B. It’s hard to run.

C. It’s too easy to sweat.    D. It’s bad for the heart rate.

2.What does the underline word ＂dehydration＂ in Paragraph 3 means the loss of ______from the body.

A. water    B. heat    C. stress    D. blood

3.Why did John Brewer make a group of people run in a room?

A. It was easier to be reduce stress.

B. It was easier to produce heat.

C. It was easier to recreate different weather conditions.

D. It was easier to record their biological measurements.

4.What should people wear while running in cold winter?

A. A hat.    B. Gloves.

C. More clothing.    D. More than one layer of clothing.

5.What’s the purpose of the passage?

A. To tell people not to run in summer.

B. To describe how runners run in winter.

C. To encourage people to run outdoors in winter.

D. To compare the advantages of running in winter and in summer.