At age 61, identical twins Jeanne and Susan no longer look exactly alike. Susan smoked for many years and is an admitted sun worshipper, whose habits Jeanne does not share. A new study of twins suggests you can blame those coarse wrinkles, brown or pink spots on too much time in the sun, smoking, and being overweight. Because twins share genes, but may have different exposures to environmental factors, studying twins allows an "opportunity to control for genetic susceptibility ," Dr. Elma D. Baron, at Case Western Reserve School of Medicine in Cleveland, Ohio, and his colleagues explain in the latest issue of Archives of Dermatology. Their analysis of environmental skin-damaging factors in 65 pairs of twins hints that skin aging is related more to environment and lifestyle than genetic factors. But when it comes to skin cancer, the researchers say their findings support previous reports that both environment and genes affect skin cancer risk. Baron's team examined facial skin of 130 twins, 18 to 77 years old, who lived mostly in the northem Midwest and Eastern regions of the US, who were attending the Twins Days Festival in Ohio in August 2002. At this time, each of the twins also separately reported how their skin burned or tanned without sunscreen, their weight, and their history of skin cancer, smoking, and alcohol drinking. The study group consisted of 52 fraternal and 10 identical twin pairs, plus 3 pairs who were unsure of their twin status. From these data, the researchers noted strong ties, outside of twin status, between smoking, older age, and being overweight, and having facial skin with evidence of environmental damage. By contrast, sunscreen use and drinking alcohol appeared related to less skin damage. Baron and his colleagues say the current findings, which highlight ties between facial aging and potentially avoidable environmental factors--such as smoking, being overweight, and unprotected overexposure to the sun's damaging rays--may help motivate people to minimize these risky behaviors. Why did Baron's team do the research on twins? A) Twins are more likely to suffer from skin cancer. B) It may guarantee the research is not influenced by genetic factors. C) It gives others an opportunity to control twins' genes. D) It helps find twins are exposed to different environments.
B
This year some twenty-three hundred teenagers (young people aged from 13 to 19) from all over the world will spend about ten months in US homes. They will attend US schools, meet US teenagers, and form impressions of the real America. At the same time, about thirteen hundred American teenagers will go to other countries to learn new languages and gain a new understanding of the rest of the world. Here is a two-way student exchange in action. Fred, nineteen, spent last year in Germany with George's family. In turn, George's son Mike spent a year in Fred's home in America. Fred, a lively young man, knew little German when he arrived, but after two months' study, the language began to come to him. Schools were completely different from what he had expected--much harder. Students rose respectfully when the teacher entered the room. They took fourteen subjects instead of the six that are usual in the United States. There were almost no outside activities. Family life, too, was different. The father's word was law, and all activities were around the family rather than the individual . Fred found the food too simple at first. Also, he missed having a car. "Back home, you pick up some friends in a car and go out and have a good time. In Germany, you walk, but you soon learn to like it." At the same time, In America, Mike, a friendly German boy, was also forming his idea."I suppose I should criticize American schools," he says. "It is far too easy by our level. But I have to say that I like it very much. In Germany we do nothing but study. Here we take part in many outside activities. I think that maybe your schools are better in training for citizens . There ought to be some middle ground between the two. After experiencing the American school life, Mike thought _ . A) German schools trained students to be better citizens B) A better education should include something good from both America and Germany C) American schools were not as good as German schools D) The easy life in the American schools was more helpful to students
B
Q: "Confidence" is probably one of the most noticeable traits in the Americans. They show confidence in the way they talk, the way they smile, the way they dress and the way they walk. Living and competing with all these confident American students, I find it extremely important to be confident as an international student and instructor. As a student, being confident means you should never hesitate to raise your hand whenever a question or a point comes to your mind. Don't mind if it sounds simple or silly. Otherwise you will never get a chance to speak in class at all. What's worse, the professors may think you are not prepared for the discussion or you do not have your own opinion on the issue--this is the last comment any graduate would like to receive. Being confident for me as a foreign instructor means calmly asking the student to repeat what he or she has said if I did not get it. Pretending to understand what you actually did not may just bring yourself embarrassment or even disgrace. But the time I most need to be confident is when my students come to my office and bargain about the grades I have given for their speeches. (The course I'm teaching here is Public speaking). Modesty is a trait highly valued in China, but it won't be of much help here if you want to survive and succeed in a good American graduate program. A professor will have the worst opinion of a student who _ . A) gives a silly or simple answer B) tries to seize any chance to speak in class C) shows no interest in the course D) is considered to have no opinion of his own
A: D
(Question)
Flying over a desert in an airplane, two scientists looked down with trained eyes at trees and bushes. After an hour's flight one of the scientists wrote in his notebook, "Look here for probable metal." Walking across hilly ground, four scientists reported, "This ground should be searched for metals." From an airplane over a hilly wasteland a scientist sent back by radio one word "Uranium". None of the scientists had X-ray eyes: they had no magic powers for looking down below the earth's surface. They were merely putting to use one of the newest methods of locating minerals in the ground -- using trees and plants as signs that certain minerals may lie under the ground on which the trees and plants are growing. This newest method of searching for minerals is based on the fact that minerals deep in the earth may affect the kind of bushes and trees that grow on the surface. At Watson Bar Creek, a mineral search group gathered bags of tree seeds. Boxes were filled with small branches from the trees. Roots were dug and put into boxes. Each bag and box was carefully marked. In a scientific laboratory the parts of the forest trees were burned to ashes andtested. Each small part was examined to learn whether there were minerals in it. Study of the roots, branches and seeds showed no silver. But there were small amount of gold in the roots and a little less gold in the branches and seeds. The seeds growing nearest to the tree trunk had more gold than those growing on the ends of the branches. If the trees indicated that there was no gold in the ground, the scientists wouldn't spare money to pay for digging into the ground. Which of the following might be the best title for this passage? A) Scientists searching for treasure with special equipment. B) New methods of doing geological study. C) Gold could be found in trees and plants. D) A new method of searching for minerals.
(Answer)
D