Read the article and select the best answer. Article: Dr Asim Syed, 32, has performed more than 100 operations at London's Hammersmith Hospital in the country's busiest transplant unit, but never imagined that he would one day become a donor himself. He stepped forward when was told his 64-year-old mother might be dead within months unless she got a new kidney . The worried surgeon brought her to London to be cared for at his hospital. However, it was not all plain sailing. Tests showed Dr Syed was the wrong blood group, so the only way was to go through a special blood-washing process. He consulted colleagues about that, but they didn't agree, because the risk of rejection is still too high. Dr Syed and his mother were then advised to consider a new way of donating and receiving, called an organ-paired. That is, Dr Syed donated his kidney to an unknown person and another donor in the chain was a successful match for his mother. The chain of three transplants took place at the same time on July 31 with Dr Syed's kidney going to a recipient in the Midlands and Mrs. Syed receiving her kidney from a person in the south of England. Just hours after donating his own kidney, Dr Syed found himself recovering in bed next to his mother. Mrs Syed said, "When I came round from my operation Asim was in the next bed and the first thing he said was, 'Mum now all your worries are over.' Tears fell down." Now mother and son are recovering well with Dr Syed already back at work. Mrs. Syed is staying with him for several months while the hospital monitors her progress. He said, "I did what anyone would do when they see a relative suffering disease. Although I wasn't able to help mum directly, by agreeing to be part of a chain, I was also very happy." Question: Why isn't it a plain sailing? Options: A: No one can treat his mother well. B: Dr Syed was the wrong blood group. C: They didn't have money to be in hospital. D: Mrs. Syed was unwilling to receive the operation.
B

Read the article and select the best answer. Article: Grasshoppers are having to change their song -- one of the iconic sounds of summer -- to make themselves heard above the noise of road traffic, ecologists have discovered. The study, published in the British Ecological Society's journal Functional Ecology, is the first to show that human-made noise affects natural insect populations. Animals use sound to communicate for many reasons, including marking out territory, warning of predators and finding mates, and although previous research shows birds, whales and even frogs change their calls in noisy environments, the impact of human-made noise on insects has been neglected until now. Ulrike Lampe and colleagues from the University of Bielefeld in Germany caught 188 male bow-winged grasshoppers, half from quiet locations and half from beside busy roads. The grasshoppers use their song to attract mates. The team then studied the differences in the two groups' songs in the laboratory. To encourage them to sing they exposed the males to a female grasshopper, and then recorded their courtship songs. Analysis of almost 1,000 recordings revealed grasshoppers living beside noisy roads produced different songs to those living in quieter locations. According to Lampe: "Bow-winged grasshoppers produce songs that include low and high frequency components. We found that grasshoppers from noisy habitats increase the volume of the lower-frequency part of their song, which makes sense since road noise can mask signals in this part of the frequency spectrum ." The team's findings are important because traffic noise could be upsetting the grasshopper's mating system . "Increased noise levels could affect grasshopper courtship in several ways. It could prevent females from hearing male courtship songs properly, prevent females from recognizing males of their own species, or _ females' ability to estimate how attractive a male is from his song," Lampe explains. Having discovered that human-made noise affects insect communication, the researchers now want to learn more about how... Question: Which of the following could be the main idea of the passage? Options: A: Bow-winged grasshoppers use their songs to communicate. B: Grasshoppers change their songs to adapt to the noisy environment. C: Grasshoppers' songs include both low and high frequency components. D: Bow-winged grasshoppers are a common species in Central Europe.
B

(Question)
Read the article and select the best answer. Article: Most schools forbid chewing gum, but in a few years they might consider changing that rule. Why? Scientists are finding evidence that gum chewing may be good for your health. It may even help improve your test scores. This exciting research is just beginning. And in the meantime, companies are also experimenting with adding vitamins, minerals, medicines, and other substances that could give gum the power to cure headaches and fight everything from serious diseases to bad breath. Other researchers are finding that gum might work better than a pill to deliver medicines and other substances into the bloodstream. That's because the lining of our cheeks can absorb certain substances more quickly than our stomachs and intestines can. That discovery could help other researchers develop medicine-containing gums that fight colds, ease headaches, battle nervousness, and more. Scientists might even create antimicrobial gums that cure bad breath. Those projects may take years, but gum scientists have already had at least one recent success: They've created a gum that could help us stay awake. Researchers have produced a gum called Stay Alert. Each stick has as much caffeine as a cup of coffee. It can take an hour for the caffeine in coffee to have its full effect, but the caffeine in Stay Alert _ in just a few minutes. The gum is easy to transport and it's stable in cold and hot climates. Unlike a pill, it doesn't require water to swallow. Those qualities make it easy for soldiers to use. For now, Stay Alert is available only to the military . The manufacturer may one day offer it for sale to the public. People who work at night, such as truck drivers and medical personnel who ride in ambulances, might benefit from a product like Stay Alert. Question: It can be inferred from the passage that _ . Options: A: stay Alert is not easy to store B: stay Alert needs water to swallow C: stay Alert is available to the public now D: we can't buy gums that cure bad breath now
(Answer)
D