问题详情：
Sitting for more than three hours a day can decrease a person's life expectancy（寿命）by two years, even if he or she is physically active and gets rid of dangerous habits like smoking, according to a study．Watching TV for more than two hours a day can worsen that problem, decreasing life expectancy by another l．4 years．
The analysis comes just two years after Australian researchers found that people who said they watched TV for more than four hours a day were 46% more likely to die of any cause than people who said they spent less than two hours a day watching TV．Those watching TV more than four hours a day were also 80% more likely to die of cardiovascular （心血管的） disease．"Sedentary （久坐的） behavior is something we need to pay attention to, beyond telling people to get 30 minutes of activity a day ,”said Peter T．Katzmaezyk． one of' the lead researchers． But while the evidence of illnesses is increasing, it remains difficult for many people to find time to get on their feet, especially if they do desk jobs．
"Try to stand as much as you can," Dr．Katzmarzyk said．"Typically when you're on the telephone you can stand and use the speakerphone Instead of emailing someone in the office, just get up and So to talk to them．" However, Dr．Katzmarzyk added, standing shouldn't be an alternative to exercising, but an alternative to sitting．"Several studies show that when you're sitting, your leg muscles are completely inactive," he said． "When you're sitting and completely inactive, this is when you run into trouble managing blood glucose （血糖）．"
29．What is the main idea of the first paragraph?
A．Watching TV too long can worsen our mental health．
B．We should he active and give up smoking．
C．Silting for too long a time can shorten one's lire．
D．Smoking too much can be harmful to health．
30．The researchers draw the conclusion on the effect of sedentary behavior by ．
A．making comparisons B．istin8 figures
C．giving examples D．classifying facts
31．What dues Dr．Katzmarzyk think of sedentary behavior?
A．It warns people to exercise 30 minutes a day．
B．It's a bad behavior worth considering seriously．
C．Sedentary behavior can lead to death at once．
D．Sedentary behavior is good for desk job workers．
32．According to Dr．Katzmarzyk, if you are sitting all the time, you may _ ．
A．phone your friends and talk about your problem
B．put on weight quickly and become more inactive
C．want to have more sugar for your meals
D．fincl it hard to keep your blood glucose proper
【回答】
CABD
知识点：健康保健类阅读
题型：阅读理解
