Read the following article and select the best answer. Article: Backpacks are convenient. They can hold your books, your lunch, and a change of clothes, leaving your hands free to do other things. Someday, if you don't mind carrying a heavy load, your backpacks might also power your MP3 player, keep your cell phone running, and maybe even light your way home. Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia2 and the Marine Biological Laboratory in Woods Hole3, Mass. 4, have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions, search-and- rescue operations, and scientific field studies, people rely increasingly on cell phones, global positioning system (GPS)5 receivers, night-vision goggles, and other battery-powered devices to get around and do their work. The backpack's electricity-generating feature could dramatically reduce the amount of a wearer's load now devoted to spare batteries, report Rome and his colleagues in the Sept. 9 Science6. The backpack's electricity-creating powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer's back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts. Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack's oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack. The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power- generating backpacks could make it possible to walk, play video games, watch TV,and listen to music, all at the same time. Electricity-generating packs aren't on the market yet, but if you do get one eventually,... Question: Backpacks are convenient because - your hands are freed to do other things. - they can hold as many things as you want to carry. - they can be very large. - you do not have to carry things with you.
your hands are freed to do other things.

Read the following article and select the best answer. Article: A new study says one part of the human brain may become smaller as the result of a condition known as jet lag. Jet lag results from flying long distances in an airplane. Jet lag interferes with a person's normal times for sleeping and waking. People with jet lag may feel extremely tired for several days. They also may have problems thinking clearly and remembering. Kwangwook Cho is a researcher at the University of Bristol in Britain. He reported the findings of his jet lag study in the publication Nature Neuroscience. The study involved twenty young women who worked for international airlines. The women had served passengers on airplanes for five years. These flight attendants flew across many countries and at least seven time zones. In the study, the flight attendants had different amounts of time to recover from jet lag. Half the women spent five days or fewer in their home areas between long flights. The other half spent more than fourteen days in their home areas. Mister Cho took some fluid from the women's mouths to measure levels of a hormone that increases during stress. He tested them to see if they could remember where black spots appeared on a computer screen. And he took pictures of their brains using magnetic resonance imaging. This is a way to measure the size of the brain's temporal lobes. It was found that the women who had less time between flights had smaller right temporal lobes. This area of the brain deals with recognizing and remembering what is seen. The same group performed worse and had slower reaction times on the visual memory test. And their saliva samples showed higher levels of stress hormones. Mister Cho says he believes the brain needs at least ten days to recover after a long trip. He says airline workers told him their ability to remember got worse after working on planes for about four years. Other studies have shown that increased feelings of stress can cause a loss of cells in the part of the brain that controls memory. Scientists say more tests are needed to study the... Question: What is the subject discussed in the test? - The cause of jet lag. - A story of a group of flight attendance. - A research about the effects of jet lag on the brain. - The importance of having enough rest after long flights.
A research about the effects of jet lag on the brain.

(Q).
Read the following article and select the best answer. Article: Luo Jingyu, 19, has four years of experience of running business. He is also a freshman in the arts department of Hubei University. Luo Jingyu is from an ordinary family. He said, "My parents told me if I wanted something I should make an effort to get it, so I earned pocket money by doing housework when I was little." The dream of running his own business grew in his heart. He said, "I want to be a successful person, like Alibaba's Ma Yun." When Luo was a junior student, he had the idea of selling lanterns when he saw many people flying Chinese lanterns in a square. Luo bought some lanterns from a store, but the sales were not as good as he had expected. Then he found another way to do business. He bought lanterns on the Internet at a very low price. Finally he easily made 5,000 yuan in two days. With a happy beginning, Luo planned to open a dress shop. "My parents didn't support me opening a dress shop, so I had to borrow 120,000 yuan for it." Although he did market research before starting, the business wasn't very good because his taste in fashion wasn't accepted by customers. The shop eventually closed down after half a year. After experiencing a big loss, he decided to do something he was familiar with --- selling painting tools. As a fine arts student, he knew the market. He convinced his friends to invest one million yuan in his shop. With a good business mind and a lot of effort, the sales of the shop reached six million yuan in a year. Even though Luo is rich, he uses a cheap cell phone and does not wear luxury clothes. He has a simple lifestyle. "It isn't easy to make money, so money should be used on something worthwhile," he said. Question: Why wasn't the dress shop successful? - He had to prepare for his exam. - The dresses he bought weren't of high quality. - Customers didn't accept his taste in fashion. - He didn't have enough money to buy beautiful dresses.
(A).
Customers didn't accept his taste in fashion.