阅读理解。
You may know about"junk food" like French fries. But do you know about "junk sleep"?
Recently, a British survey found that electronic products in teenagers' bedrooms are affecting their sleep.
The survey was done among 1 000 British kids aged 12 to 16. It found that 30 percent of them got just
4 to 7 hours sleep every day. But experts say they need 8 to 9 hours.
Almost a quarter of the kids said they fell asleep more than once a week while watching TV, listening to
music or using other electronic products.
"This is very worrying," said Dr Chris Idzikowski, a British expert. "We call it 'junk sleep'. It means you
don't get enough sleep and the quality of the sleep is bad too. If you don't get good rest, you don't perform
well in school the next day."
The survey found that 40 percent of the kids felt tired each day, with girls aged 15 to 16 feeling the worst.
Nearly all the teenagers have a phone, MP4 or TV in their bedroom. And around two-thirds of them have all
three.
1. "Junk food" and "junk sleep" are similar to each other in the way that _____.
A. they are both good to people's health
B. they are both low in quality
C. people enjoy both in their spare time
D. they are both produced in factories
2. _____ of the children surveyed sleep only 4 to 7 hours a day.
A. 300
B. 250
C. 500
D. 400
3. Which of the following is true according to the passage?
A. Teenagers need 4 to 7 hours of sleep each day.
B. Teenagers spend too much time on electronic products.
C. Girls aged 15 to 16 spend the least time on electronic products.
D. Electronic products harm the teenagers by producing harmful rays.
4. The best title for the passage would be _____.
A. Electronic Products
B. A Survey about Kids
C. The Importance of Sleeping
D. Junk Sleep
30S内，NO增加了0.3mol，则在30S内，该反应的平均反应速率正确的是 
[Cu（NH3）3]Ac•CO（aq）（△H＜0）
