C. some educators cant connect a social networking site easily.
D. some educators find it difficult to close a social networking site.
3. The word “their” in the last paragraph may refer to .
A. the experts
B. the social networking sites
C. the schools
D. the students
4. What might be the most suitable title for the passage?
A. Lessons online
B. Friendship online
C. Danger online
D. Information online
Saving energy can not only reduces pollution, but can also save your money. Here are some easy things that are guaranteed1 to save your money:
Lets imagine you live in a house where there are five people who each takes a sevenminute daily shower. If you have an oldfashioned shower head that uses five gallons of water a minute, your house will use about 64,000 gallons of water a year for showers. If you buy a new shower head, using 2.5 gallons of water per minute, you will save 32,000 gallons of water a year.
Most lighting in homes consists of ordinary incandescent light bulbs（白炽灯泡）
, which change electricity into light by heating a filament2. They are not efficient because only about 10 percent of the electricity used produces visible light, while the rest goes into heat. Compact fluorescent light（节能荧光灯）
is three to four times more efficient. Replacing just one 75watt incandescent bulb with an 18watt compact fluorescent will save about 570 kilowatthours of electricity over the fluorescents 10,000hour lifetime. And, because fluorescents last longer, you wont have to keep changing the bulb. Over the life of the compact fluorescent, youll probably save between ＄3 and ＄15 per year.
Even when they are not in use, many appliances3 like televisions continue to use small amounts of electricity. If you have a rarely used appliance, such as a TV or clock radio in a guest room, pull its plug and then plug it in on those rare4occasions when it is going to be used.
Many people have gotten into the habit of leaving their computer and other home or office equipment on all the time. This wastes energy and money. If you are going to be away from the computer for one or more hours, turn it off. In addition, make sure to have the screen go dark after 15 minutes of no use.
【生词注释】
1. guaranteevt. 保证；担保
2. filamentn. 细丝（如电灯泡内的灯丝）
3. appliancen. 器具；器械；装置
4. rareadj. 稀少的；罕见的
根据短文内容，从A-F中选出每段的最佳标题。选项中有一项多余
A. Choose a compact fluorescent
B. Water and electricity
C. Pull the plug
D. Ways to save energy and money
E. Use a new shower head
F. Turn off the computer
1. 2. 3. 4. 5.
Between their crazy schedules and upsidedown circadian1 rhythms, teens have always been somewhat sleepdeprived. Now technology is making it worse.
Teens are not just texting, instantmessaging and surfing Facebook all day, but theyre sleeping with their cell phones or laptops too. 1 And doctors and parents, many of them raised in an era2 when phones were attached to walls, are concerned.
“So many teens are having sleep issues, and parents arent necessarily regulating3 the use of the electronic devices enough,” says Margie Ryerson, a therapist4. “Its impossible to wind down and relax the body, the mind, the senses and be ready to fall asleep.”
“2” says San Francisco. “As long as parents allow teens to have these devices in their bedrooms at night, teens will be tempted to use them.”
Ryerson calls it the CNN syndrome of teenhood-roundtheclock reports on breaking news about everything from homework to wardrobe5 choices to icecream cravings.
Sleep deprivation6 is linked to memory and concentration problems, anxiety and depression, and moodiness. “Many people assume these problems arise directly from adolescence, which is not really true,” he says. “3 Latenight texting can certainly make the situation worse.”
The psychology behind this constant7 contact is certainly understandable, Ryerson says. “4 They wont be considered important and significant in their peer group, if they dont know whats going on. If theyre on top of everything, they belong,” she says.
What helps, at least for younger kids, says Ryerson, is parental involvement. “If all of their friends are all able to text into the early hours of the night, it is hard for a middle or high schooler to set the limit themselves. 5”
“As parents, we want our kids to be happy, healthy and responsible,” she says, “and the most necessary requirement for achieving balance is to first take care of ourselves physically - eating well, exercising and getting enough sleep.”
【生词注释】
1. circadianadj. 生理节奏的；昼夜节律的
2. eran. 纪元；历史时期
3. regulatevt. 控制；管理
4. therapistn. 治疗专家
5. wardroben. 衣柜；衣橱
6. deprivationn. 剥夺；被夺去；丧失
7. constantadj. 始终如一的；恒久不变的
根据短文内容，选出能填入空白处的最佳选项。选项中有两项多余
A. Actually they dont want to sleep.
B. The real issue is sleep deprivation.
C. If parents permit their children to use computer, they will be happy.
D. Or rather, not sleeping.
E. We all know teens dont get enough sleep in general.
F. It comes from wanting to avoid being left out.
G. Often they appreciate parents stepping in.
