题目内容：

    Everyone knows that walking is one of the best means of exercise for health, so physicians often recommend 150 minutes a week. But that’s a measure of volume (量). What about the walking speed? Does that make a difference? A recent paper indicates the answer may be yes.

Previous research had only focused on total amounts of exercise in minutes or steps. A team of experts in Sydney looked at whether people who walked similar distances but at different speeds gained more or less health benefits

The researchers studied 11 English and Scottish population-wide reports that included more than 50,000 regular walkers with an average age of late 40s. The walkers were grouped according to four walking speeds: slow, average, brisk(轻快的) and fast. Lastly, the researchers figured out the death( from heart disease and cancer) rate during an average follow-up period of 9.2years.

New researchers showed marathoners had less arthritis(关节炎) than non-runners.

Participants who walked at an “average” speed, as opposed to ” slow ” , had a 20 percent lower risk of death. Those walking at a “ brisk ” or “ fast ” pace enjoyed an additional 4 percent lower death rate. While the best speeds vary with one’s own age and fitness, a pace below 20 minutes per mile is considered average, and below 18 minutes per mile is considered brisk. All the benefits came from lower heart-related deaths. Walking pace had no effect on cancer rates.

“Our paper is the first paper to keep apart walking pace from the physical activity volume ,”

Explained Emmanuel Stamatakis , a professor of the Charles Perkins Center. “We also took steps to role out ( 排除 ) the possibility that the slow walkers were in poor health to begin with.”

“Walking more is better than walking less. But don’t fall into the trap of thinking that any walk improve health. Keep out of the ‘ slow ’ zone. Make sure you’re putting some effort into your walk”, Stamatakis noted. “ An appropriate effort for those in a comfortable walking routine might be slightly out of breath.”

When you’re short of time, simply walk faster to increase the pay-off. “ A faster pace means you are challenging yourself to make adaptations for better health and fitness,” said Stamatakis.

1.What’s the finding of the recent paper?

A.Slow walkers are in poor health at first.

B.Walking speed influences one’s health.

C.Walking pace has some effect on cancer rates.

D.Walking 150 minutes a week is good for health.

2.How were the walkers sorted in the research?

A.They were divided into groups by walking pace.

B.They were put into different age group.

C.They were groups by health condition.

D.They were organized by nationality.

3.What can we know about the research?

A.Participants are from eleven countries.

B.Participants include people of all ages.

C.It collected data during an average of 9.2 years.

D.It focused on total amounts of exercise in minutes.

4.What’s Stamatakis’s advice for those in a comfortable walking routine?

A.Working more. B.Walking a little faster.

C.Trying other exercise. D.Changing the present lifestyle.