Question: I'm taking a test and have to guess the right answer to the question after the article. Article: Dr. Jack M. Gwaltney, Jr. a professor at the University Of Virginia School Of Medicine infected six student volunteers with virus, the most common cause of colds. A few days later, when they were coughing and sneezing, he gathered 37 more people and divided them into three groups. Group 1 members spent three days and nights in the same room with one of the infected students, separated by a screen so they couldn't touch one another. Group 2 sat around a table while an infected volunteer talked, coughed and sang to them. Group 3 held hands with an infected student for ten seconds, and then touched their own noses or eyes. Although most scientists at the time, the mid-70s, believed colds were spread by virus-laden droplets spread through the air when infected people coughed or sneezed, Gwaltney suspected physical contact might play an important role. Sure enough, of the 15 people who had touched a student volunteer, 11 became infected--compared with only one of those who had been sitting at the table, and none who had spent three days and nights together. "The best evidence we have is that hand-to-hand contact is the most efficient way of transmitting virus," says Gwaltney. The study was one of a series that helped establish Gwaltney's reputation as a leading authority. Dr. Robert Couch says, "It would not be inappropriate to call him Mr. Common Cold." When Gwaltney is asked how close scientists are to finding a cure, he replies: "If you mean 'get rid of', I don't think we're going to be able to do that with cold viruses any time soon. But if you look in the dictionary, you'll see that 'cure' is explained as a successful treatment. And we're not just getting more effective at treating the symptoms --we're getting at the root cause too. " Question: The result of the experiment shows that _ plays an important role in the infection of colds. Options: A: sneezing at the infected person B: touching the infected person C: sitting together with the infected person D: talking with the infected person
Answer: B

Question: I'm taking a test and have to guess the right answer to the question after the article. Article: Sure,you've watched extreme pet sports on Animal Planet. But did you know that there's a whole world of athletic activities for dogs right in our area? There are some reasons for considering taking part in such activities. Such sports strengthen the close feelings between dog and owner,and also benefit your pup's body and mind." Dogs that are tied with chains often have behavioral problems," says Lee Morgan. "They love to go out and play as much as we do." Of course,many of these sports require some amount of practice,and some breeds are simply better at certain activities than others .But all dogs can participate in the following games. Frisbee Dogs This sport requires you to throw as many Frisbees as your dog can catch in a 60second time period. The further out your dog catches the Frisbee,the more points you rack up. Extra points are awarded if your pet catches the Frisbee while it's still in the air. Mid Atlantic Disc Dogs (MADDogs) hosts local competitions and offers informal instruction in local parks or even in people's backyards. Flyball Dogs The sport has been around since 1970s.Flyball is a relay race with four dogs in a team. Each must jump four hurdles spaced with 10 feet apart and then land on a springloaded box that shoots out a tennis ball. The dog must then catch the ball and run back over the four hurdles. Once that's done,the next dog can go. The first team that successfully completes the course wins the competition. There are a number of local teams,including 4 Dog Night,which holds classes for beginners and intermediate players and is always looking for new team members. The Beltway Bandits is another team,based in Leesburg,that hosts private classes and competitions. Question: Dogs that are always tied with chains often have behavioral problems because _ . Options: A: there are no close feelings between dog and owner B: many of them lack enough sports or exercises C: there are no local athletic activities or sports for dogs D: dogs love to go out and play as much as human beings
Answer: D

Question: I'm taking a test and have to guess the right answer to the question after the article. Article: From furniture to jewelry, from the medical industry to civil engineering,three--dimensional printing can turn all sorts of ideas into objects. "I wanted to print large objects such as buildings,"said Behrokh Khoshnevis,professor of the University of Southern California.He planned to construct a house in 24 hours by applying 3D printing techniques,but he admitted there would be difficulties in meeting his goal. "For example,if you run out of ink while printing on paper,you will throw that paper away.But you cannot throw half completed buildings away if your material gets stuck,"he said.Although the printed house is not available to visit,there is a chance for people in Shanghai to see items printed in 3D. The Belgium-based company Materialize NV is currently holding a 3D printing exhibition in Shanghai that started in late 2012 and will continue until the middle of this year.The company is eager to show Asia what is possible with 3D printing. "All the pieces shown here are what cannot be made through traditional techniques. A good example of this customization is hearing aids More than l0 million people already use 3D printed hearing aids.all made according to the size of their ear."said Wim Michiels, executive vice-president at Materialise NV. "You can produce anything whenever and wherever you like.You don't need to set-up production lines for pieces that only need a limited amount of product.Setting up a production Line is a tot of work, takes a long time and is very expensive for a limited number of pieces" said Michiels. Kim Francois,managing director of Matcrialise China,said their European and American clients have at ready made the next step toward additive manufacturing with small-series production such as hearing aids. Question: According to Khoshnevis,what is the main difficulty in printing buildings? Options: A: Time. B: Technique. C: Space. D: Material.
Answer:
D