How many hours do you spend sitting in a chair every day？Eight hours in the office plus three hours in front of the TV after work is the usual situation for many people．
You probably don't need an expert to tell you that sitting too much is not good for your health-from an increased risk of heart disease and obesity（肥胖） in the long term，to reduced cholesterol（膽固醇） maintenance in the short term，not to mention the pressure on your neck and spine（脊柱）．
To make matters worse，a growing body of research suggests that the negative effects of sitting too much cannot be countered with a good diet and regular exercise，according to an article in The New York Times．The article reported that a study of nearly 9，000 Australians found that for each additional hour of television a person watched per day，the risk of dying rose by 11 percent．In other words，sitting is killing us．
Stand up for health．Health experts suggest we break up those many hours spent sitting with more hours spent standing．
The BBC and the University of Chester in the UK conducted a simple experiment with a small group of 10 volunteers who usually spent most of the day sitting．They were asked to stand for at least three hours a day．The researchers took measurements on days when the volunteers stood，and when they sat around．When they looked at the data，there were some striking differences．Blood sugar became level after a meal much quicker on the days when the volunteers in the study stood compared with the days they spent in a chair．Standing also burned more calories（熱量單位：卡路里）-about 50 calories an hour．Over the course of a year that would add up to about 30，000 extra calories，or around 3.63 kilograms of fat．
John Buckley，a member of the research team，said that although doing exercise offers many proven benefits，our bodies also need the constant，almost imperceptible（感覺(jué)不到的） increase in muscle activity that standing provides．Simple movement helps us to keep our all-important blood sugar under control．
The researchers believe that even small adjustments，like standing while talking on the phone，going over to talk to a colleague rather than sending an e-mail，or simply taking the stairs instead of the elevator，will help．
（Note：Answer the questions or complete the statements in NO MORE THAN TEN WORDS．）

78．According to the context，the underlined expression"be countered with"in Paragraph 3 can best be replaced by"

be prevented/reduced by

be prevented/reduced by

"．
79．The two findings of the simple experiment conducted by the BBC and the University of Chester in the UK are that standing

helps blood sugar become level quicker and burns more calories

helps blood sugar become level quicker and burns more calories

．
80．Why is standing better than doing exercise according to John Buckley？

Standing provides the constant，almost imperceptible increase in muscle activity

Standing provides the constant，almost imperceptible increase in muscle activity

．
81．What does the passage mainly want to tell us？

People should stand for health instead of sitting too much

People should stand for health instead of sitting too much

．