单选题Not content to ______ along in ignorance and on her own, Patty began reading everything she could get and immediately set out to develop a network of gardening colleagues.

单选题This is but a ______ of the total amount of information which the teenager has stored.

单选题You mustn't forget ______ your credit card when you come here tomorrow. A. to bring B. bring C. to take D. take

单选题It's not only humans that flourish in large settlements. Some ants find urban life so accommodating that their populations explode and they form supercolonies in cities. "One of the most common house ant species might have been built for living in some of the smallest spaces in a forest, but the ants have found ways to take advantage of the comforts of city living," Purdue University said in a statement. Grzegorz Buczkowski, a Purdue University research assistant professor of entomology, discovered odorous house ants live in supercolonies, creating complex networks entomologists have never seen with the species before now. He found that odorous house ant colonies become larger and more complex as they move from forest to city and act somewhat like an invasive species, the university said. "The ants live about 50 to a colony with one queen in forest settings but explode into supercolonies with more than 6 million workers and 50 000 queens in urban areas," the university explained. "This is a native species that's doing this," said Buczkowski, whose results are published in the early online version of the journal Biological Invasions. "Native ants are not supposed to become invasive. We don't know of any other native ants that are outcompeting other species of native ants like these," Buczkowski said. Odorous house ants live in hollow acorn shells in the forest. They're called odorous because they have a coconut (椰子)-or rum-like smell when crushed. They're considered one of the most common house ants, Purdue said. In semi-natural areas that are a cross of forest and urban areas, such as a park, Buczkowski said he observed colonies of about 500 workers with a single queen. "It's possible that as the ants get closer to urban areas they have easier access to food, shelter and other resources," he said. "In the forest, they have to compete for food and nesting sites," Buczkowski said. "In the cities, they don't have that competition. People give them a place to nest, food to eat. " Buczkowski observed the ants in three different settings on and around the Purdue campus. He said it might be expected that if the odorous house ants were able to multiply into complex colonies, other ants would do the same. But Buczkowski found no evidence that other ants had adapted to new environments and evolved into larger groups as the odorous house ants have, Purdie said. "It's possible that odorous house ants are better adapted to city environments than other ant species or that they had somehow outcompeted or dominated other species," he said. "This raises a lot of questions we'd like to answer. " Buczkowski said understanding why the supercolonies form could lead to better control of the pests in homes, as well as ensuring that they don't outcompete beneficial species. Future studies on odorous house ants will include studying the ant's genetics and trying to understand the effects of urbanization of odorous house ants, Purdue said.

单选题All of the plants now raised on farms have been developed from plants ______ in the wild.

单选题 Is language, like food, a basic human need without which a child at a critical period of life can be starved and damaged? Judging from the drastic experiment of Frederick in the thirteenth century, it may be. Hoping to discover what language a child would speak if he heard no mother tongue, he told the nurses to keep silent. All the infants died before the first year. But clearly there was more than lack of language here. What was missing was good mothering. Without good mothering, in the first year of life especially, the capacity to survive is seriously affected. Today no such severe lack exists as that ordered by Frederick. Nevertheless, some children are still backward in speaking. Most often the reason for this is that the mother is insensitive to the signals of the infant, whose brain is programmed to learn language rapidly. If these sensitive periods are neglected, the ideal time for acquiring skills passes and they might never be learned so easily again. A bird learns to sing and to fly rapidly at right time, but the process is slow and hard once the critical stage has passed. Experts suggest that speech stages are reached in a fixed sequence and at a constant age, but there are cases where speech has started late in a child who eventually turns out to be of high IQ. At twelve weeks a baby smiles and utters vowel-like sounds; at twelve months he can speak simple words and understand simple commands; at eighteen months he has a vocabulary of three to fifty words. At three he knows about 1,000 words which he can put into sentences, and at four his language differs from that of his parents in style rather than grammar. Recent evidence suggests that an infant is born with the capacity to speak. What is special about man's brain, compared with that of the monkey, is the complex system which enables a child to connect the sight and feel of, say, a teddy-bear with the sound pattern 'teddy-bear'. And even more incredible is the young brain's ability to pick out an order in language from the mixture of sound around him, to analyze, to combine and recombine the parts of a language in new ways. But speech has to be induced, and this depends on interaction between the mother and the child, where the mother recognizes the signals in the child's babbling, grasping and smiling, and responds to them. Insensitivity of the mother to these signals dulls the interaction because the child gets discouraged and sends out only the obvious signals. Sensitivity to the child's non-verbal signals is essential to the growth and development of language.

单选题It's natural that she ______ do so.

单选题Speaker A: Very pleased to meet you.Speaker B: ______ A. How do you do? B. Oh, you must be John. I can hardly recognize you. C. The pleasure is mine. D. You're welcome.

单选题______ in an atmosphere of simple living was what her parents wished for.

单选题As Christmas approached, with people (crowded) department stores, restaurants, theaters and movie houses, the downtown area (was), (as always), the (busiest).

单选题By the time he arrives in Beijing tomorrow, we ______ here for two days. A. have been staying B. have stayed C. shall stay D. will have stayed

单选题 香港是仅次于纽约和伦敦的全球第三大金融中心。香港实行“一国两制(one country，two systems)”，以良好的治安、自由的经济体系及完善的法制闻名于世。作为一个多元文化中心，香港是全球最富裕、最繁荣、最安全及人均寿命最长的地区之一。香港也是世界上重要的经济中心和航运枢纽，有“东方之珠”的美誉。同时，香港还是全球最受欢迎的旅游胜地之一，旅游业是香港四大支柱产业之一，很多知名景点都深受旅客欢迎。

单选题 In this situation, the only thing_____can be done now is to stop polluting our environments.

单选题Cindy: John, where are the cookies? Don't tell me you ate them all! John: Yes, I did.______.

单选题Couples are restricting the size of their families in the UK because of cash worries brought on bvthe financial crisis and the subsequent decline.We’re now up to nearly 3.7 million families whelthere

单选题The purpose of a ______ is to cut down imports in order to protect domestic industry and workers from foreign competition. A. tax B. toll C. fee D. tariff

单选题What are those of us who have chosen careers in science and engineering able to do about our current problems? First, we can help destroy the false impression that science and engineering have caused the current world trouble. On the contrary, science and engineering have made vast contributions to better living for more people. Second, we can identify the many areas in which science and technology, more considerably used, can be of great service in the future than in the past to improve the quality of life. While we can make many speeches, and pass many laws, the quality of our environment will be improved only through better knowledge and better application of that knowledge. Third, we can recognize that much of the dissatisfaction we suffer today results from our very successes of former years. We have been so greatly successful in attaining material goals that we are deeply dissatisfied that we cannot attain other goals more rapidly. We have achieved a better life for most people, but we are unhappy that we have not spread it to all people. We have reduced many sources of environmental disasters, but we are unhappy that we have not conquered of them. It is our raised expectations rather than our failures which now cause our distress. Granted that many of our current problems must be cured more by social, political, and economic instruments than science and technology, yet science and technology must still be the tools to make further advances in such things as clean air, clean water, better transportation, better medical care, more adequate welfare programs, purer food, conservation resources, and many other areas.

单选题I'd rather you (would go) by train

单选题From the passage we know that welfare reform aims at______.

单选题When I saw Dave, he ______ .