Plants have family values, too; it seems, with new research suggesting they can recognize close relatives in order to work together. An ability to tell family from strangers is well known in animals, allowing them to cooperate and share resources, but plants may possess similar social skills, scientists believe. Susan Dudley and Amanda File of McMaster University in Ontario, Canada, report they have demonstrated for the first time that plants can recognize their kin. This suggests that plants, though lacking recognition and memory, are capable of complex social interactions. "Plants have this kind of hidden but complicated social life," Dudley said. The study found plants from the same species of beach-dwelling wildflower grew aggressively alongside unrelated neighbors but were less competitive when they shared soil with their families. Sea rocket, a North American species, showed stronger and healthier root growth when planted in pots with strangers than when raised with relatives from the same maternal family, the study found. This is an example of kin selection, a behavior common in animals in which closely related individuals take a group approach to succeeding in their environment, the researchers said. Kin selection also applies to competition, because if family members compete less with each other, the group will do better overall. "Everywhere you look, plants are growing right up next to other plants," Dudley said," Usually it's a case of each plant for itself. But sometimes those plants are related, and there are benefits to not wasting resources on being competitive, and there is not really a cost to not being competitive as long as your neighbor is also not being competitive." Learning and memory appear to be important for kin recognition in animals, but this isn't an option for plants, she noted. Some researchers speculate that plants communicate through their roots, identifying themselves using tiny chemical signatures specific to each plant's family. Plants' kin selection is to _ . A) grow well B) compete with other kinds of plants C) strengthen the relationship among siblings D) find which one is the best
B
(Question)
Mark Twain's works are enjoyed worldwide. His real name was Samuel Langhorne Clemens and he was born on November 30th, 1835, in the village of Florida, Monroe County, Missouri. After his father's death in 1847, Twain was apprenticed to a printer and wrote for his brother's newspaper. Later, Twain worked as a licensed Mississippi riverboat pilot, adopting his name from the call ('Mark twain!'--meaning by the mark of two fathoms) used when sounding river shallows. After the Civil War, Clemens brought an end to the steamboat traffic and moved to Virginia City. On February 3, 1863, 'Mark Twain' was born when he signed a humorous travel account with his new name. In 1864, Twain went to San Francisco to work as a reporter. He traveled in France and Italy and his experience were recorded in 1869 in the Innocents Abroad, which brought him wide popularity, and made fun at both American and European prejudices and manners. In 1870 he married Olivia Langdon. Together they relocated to Harford a year later. Meanwhile, Twain continued to lecture in the United States and England. Between 1876 and 1884 he published several masterpieces, including Tom Sawyer, the Prince and the Pauper, Life on the Mississippi, and Huckleberry Finn. In the 1890s, Twain lost most of his earnings in financial speculations and in the downhill of his own publishing firm. The death of his wife and his second daughter brought a sense of gloom in the author's later years, which is seen in writings and his autobiography. Twain died on April 21st, 1910. Which of the following works made Mark Twain begin to be popular? A) Huckleberry Finn B) The Prince and the Pauper C) The Innocents Abroad D) Life on the Mississippi
(Answer)
C
Ques: Today, we know that the role of vitamins and minerals goes way beyond the prevention of deficiency diseases to actually preventing cancer and heart disease, the most fearsome killers of our time. With this knowledge has come the widespread call for nutritional supplementation -- and a confusing group of vitamin, mineral, and supplements lining the supermarket shelves. Far from contributing to better health, however, nutritional supplements threaten to turn a scientific breakthrough into a nutritional disaster. _ of vitamins and minerals -- especially vitamins A, C, and E-- would have consumers believe that the little vitamin pill in the bottle is all they need for good health. Take your vitamins in the morning, and you're covered. It's okay to eat fast foods for the rest of the day or skip meals to achieve today's fashionably skinny look. But vitamins and minerals are only one part of the nutritional puzzle. A diet rich in fiber and balanced in carbohydrates and protein is essential for good health. You can't get these things from a nutritional supplement. The focus on vitamin and mineral supplements may actually be robbing us of the full nutrition we seek. And no supplement can compare to the quality of nutrition found in natural sources. For example, our bodies turn carotenes from plant foods into vitamin A. Many supplements contain a single carotene, but natural sources are rich in many different carotenes. Many supplements contain a form of vitamin E that is made from chemicals, when natural vitamin E is more readily absorbed and used by the body. And science is still discovering the wealth of nutrients in foods. You'd be hard-pressed to find a supplement as nutritionally comprehensive and powerful as a balanced diet. Even if you could, you'd pay much more than if you got the same nutritional value from natural sources. But perhaps the greatest danger presented by nutritional supplements comes from the very real risks presented by self-medication. Anyone can walk into the market and buy as many... What has given rise to the great need for nutritional supplements? A) The knowledge of deficiency diseases. B) The low prices of nutritional supplements. C) The frighteningly high death rate from cancer and heart disease. D) The information about the role of vitamins and minerals in health.
Ans: D
Ques: We knew Sylvia and Jack had problems with their flats, but we hadn't been told the details. Not until they came for a weekend in October, that is. At dinner on the Friday evening Kitty said, "You wrote that the flat wasn't quite what you expected. Of course it could be too small. You're sharing with another couple, aren't you?" "Were sharing. Mother." Sylvia replied. "It really wasn't necessary." Jack explained proudly, "I've had a big rise, and we can easily manage. It's much better to be independent." "Oh, much," I agreed "What was the trouble?" Kitty asked, impatient and unwilling to let her go. "Nothing much." Sylvia said, "The flat is fine. It was the other couple. Sally and Tom Ford. You've never seen such an untidy pair. We shared the sitting room and the kitchen and the bathroom and got fed up with the mess of it all." "And what made it worse," Jack put in. "was that they accused us of the same sort of thing. Tom and I nearly came to blows when he locked up some of their wedding presents we were all using, as they used ours, naturally." "You take a chance when you make a sharing arrangement." Kitty said. "I am in my own flat." Sylvia said, "Sally and Tom left a month ago." "We could have left instead," Jack said, "But why we should leave? After all, the flat was in out names, not theirs. We were glad to see the back of them." Two weeks later Kitty and I retuned their visit for lunch on Sunday. It was the first time we had been to their flat. To say that we were shocked is not true, because we know our daughter extremely well. The flat had fairly recently been in quite good condition; it was now a chaos. I did not know how anyone could possibly live there. But Sylvia noticed nothing. From the passage we can learn that _ . A) Sylvia and Jack were spoiled by their parents. B) Sylvia and Jack were a pair of great ability C) Sylvia and Jack had fights with Sally and Tom D) Sylvia and Jack were in fact an untidy pair.
Ans:
D