题目内容
If your head is overheating, you are very likely to yawn(打哈欠) soon, according to a new study that has found the main purpose of yawning is to control brain temperature. The study explains several mysteries about yawning, such as why it’s most commonly done just before and after sleeping, why certain diseases lead to too much yawning, and why breathing though the nose often stops yawning.
“Brains are like computers,” Andrew Gallup, a researcher in the department of Biology at Binghamton University who led the study, said. “They operate best when cool.”
He and his co-workers Micheal Miller and Anne Clark did researches on yawning in parakeets(长尾小鹦鹉) , which have relatively large brains, live wild in Australia, often experience temperature changes, and, most importantly, do not yawn when others yawn, as humans and some other animals do.
For the study, the scientists put parakeets under three different conditions: increasing temperature, high temperature and normal temperature. While the frequency(频率) of yawns did not increase under the latter two conditions, it increased greatly when the researchers increased the temperature.
It’s now believed yawning operates like a radiator(散热器).
If air in the atmosphere is cooler than the brain and body temperatures, taking it in quickly cools blood, which in turn cools the brain. The new findings also explain why tired people often yawn. Both tiredness and sleep loss can increase brain temperature, while yawning can cool down the brain.
In the future, researchers may focus more on brain temperature and its role in diseases and their symptoms. But the new study on yawning changes the popular idea that yawns are just signs of getting tired of something.
49. What’s the best title for the passage?
A. Why don’t people yawn at normal temperature?
B. The yawn explained—it cools your brain.
C. Yawning operates like a radiator.
D. The cause of yawning—finally found out.
50. The main reason why researchers chose parakeets to do the research is that parakeets______.
A. have very large brains
B. live wild in Australia
C. are not affected by others’ yawning
D. experience frequent temperature changes
51. The writer may suggest doing all of the following to stop yawning EXCEPT______.
A. breathing through the nose
B. turning up the heat
C. enjoying some cool wind
D. putting a cold towel on your forehead
52. In which section of a newspaper would you most probably read this passage?
A. Discovery. B. Education. C. Health. D. Mystery.
49---52 BCBA
解析
EBay will launch an online group gift-buying service today designed to make it easier for several people to chip in, buy and pay for gifts using their social-network and e-mail contacts.
EBay North America Vice President Christopher Payne says it is going to be a major step forward in social commerce, which is the still-small practice of selling products through social networks.Online retail experts aren't as certain, but eBay says the new tool makes it easier for friends and relatives to chip in (凑钱) for gifts because it eliminates the headache of collecting contributions.It can also be used for family members to pitch in to buy, say, an expensive child seat for a mother.
Anything on eBay that's available immediately, rather than up for bid, can be purchased this way starting today at groupgifts.eBay.com.If members of an extended family wanted to buy a gift for one member, one person would choose a gift — or have one recommended by eBay — and invite family members to chip in using Facebook or e-mail.Those who wanted to join in would choose an amount to contribute (or agree to pay a requested amount) and pay using either PayPal or a credit card.They could also add a personal note.
If enough people don't chip in, the organizer can ask people to contribute more or choose a less expensive gift.
"I see myself using this most in cases when I typically might not buy someone what they want because of price," says Nitzan Shaer of Boston, who was part of an online test of the site.
EBay, with its 200 million products, millions of sellers and mobile commerce proficiency, is a logical place to pull together the products, groups of buyers and payment tools, Payne says.
At least 12 sites, such as FrumUs.com and eDivvy.com, facilitate (便于,利于) group purchases but don't sell products.Although a handful of retailers, including Victoria's Secret and 1-800-Flowers, sell products through Facebook, Payne says he expects social commerce will take off as rapidly as shopping using mobile devices.EBay did more than $600 million in sales on mobile devices last year and expects mobile sales to increase to $1.5 billion this year.
Although one in five consumers surveyed said they'd used Facebook for shopping in the past year, 88% said they would not be buying holiday gifts through a social network, mobile phone or smartphone.Of these, 26% were reluctant because of security or privacy concerns, and 20% were unclear about the benefits of using phones or Facebook to shop.
1.What procedure should be followed if your extended family intends to buy your grandpa an 80th birthday gift?
①Asking family members to contribute more money if enough members don’t chip in
②Choosing a gift at groupgifts.eBay.com
③Paying using PayPal or a credit card
④Contributing or agreeing to pay a requested amount of money via Facebook or e-mail
A.②-①-③-④ |
B.①-③-②-④ |
C.②-④-①-③ |
D.②-③-④-① |
2.Where can we most probably read this text?
A.In a research paper |
B.In a travel magazine |
C.In a microblog |
D.On a website |
3.What does “it” mean in the 2nd paragraph?
A.The online group gift-buying service |
B.People’s social-network and e-mail contacts |
C.A major step forward in social commerce |
D.The still-small practice of selling products through social networks |
4.It can be inferred from the text that ______.
A.through eBay’s new tool, 200 million products on eBay are available to online shoppers |
B.social commerce can eliminate the headache of collecting contributions |
C.eBay’s new tool will gain mass adoption by online shoppers |
D.with the help of eBay’s new tool, FrumUs.com and eDivvy.com will also sell products |