单选题In scores of experiments, scientists are changing the genetic endowments of plants and animals, and the results could______ a revolution in farm fields, feedlots and dairy barns. A. Spawn B. bring C. instigate D. plot

单选题The ponderous pine, a towering resident of dry regions of the United States,______ survives and thrives where other trees fail.

单选题You need to rewrite this sentence because it is ______ . The readers will have difficulty in understanding it. A. comprehensive B. alternative C. deliberate D. ambiguous

单选题Jim cooperated on the condition that he would be ______ from prosecution. A. immune B. insolated C. isolated D. avoidable

单选题Prof. Smith ______ forty or so when I first met him at the International Peace Conference in Geneva.

单选题Many artists believe that successful imitation, far from being symptomatic of a lack of originality, is the step in learning to be ______.

单选题Doctors must inform ______ parents about the low odds of success in fertility treatments. A. protective B. respective C. prospective D. perspective

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 H 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 the 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 makes vowel-like sounds; at twelve months he can speak simple words and understand simple commands; 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 be 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 toy-bear with the sound pattern "toy-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 nonverbal signals is essential to the growth and development of language.

单选题One of the most interesting things to come out of the environmental issues meeting was the fact that we certainly do not have a ______of energy sources; therefore, we must what we do have.

单选题The decision will give renewed ______ to the economic regeneration of backward regions. A. index B. impulse C. impact D. impetus

单选题{{B}}Text 4{{/B}} The rise of multinational corporations, global marketing, new communications technologies, and shrinking cultural differences have led to an unparalleled increase in global public relations or PR. Surprisingly, since modem PR was largely an American invention, the U. S. leadership in public relations is being threatened by PR efforts in other countries. Ten years ago, for example, the world's top five public relations agencies were American-owned. In 1991, only one was. The British in particular are becoming more sophisticated and creative. A recent survey found that more than half of all British companies include PR as part of their corporate planning activities, compared to about one-third of U. S. companies. It may not belong before London replaces New York as the capital of PR. Why is America lagging behind in the global PR race? Firstly, Americans as a whole tend to be fairly provincial and take more of an interest in local affairs. Knowledge of world geography, for example, has never been strong in this country. Secondly, Americans lag behind their European and Asian counterparts in knowing a second language. Less than 5 percent of Burson-Marshall's U. S. employees know two languages. Ogilvy and Mather has about the same percentage. Conversely, some European firms have half or more of their employees fluent in a second language. Finally, people involved in PR abroad tend to keep a closer eye on international affairs. In the financial PR area, for instance, most Americans read the Wall Street Journal. Overseas, their counterparts read the Journal as well as the Financial Times of London and The Economist, publications not often read in this country. Perhaps the PR industry might take a lesson from Ted Turner of CNN (Cable News Network). Turner recently announced that the word "foreign" would no longer be used on CNN news broadcasts. According to Turner, global communications have made the nations of the would so interdependent that there is no longer any such thing as foreign.

单选题Arriving anywhere with these possessions, he might just as easily ______ for a month or a year as for a single day.

单选题Space is full of unseen {{U}}hazards {{/U}}among which are cosmic rays.

单选题Which of the following best summarizes the main idea of the first paragraph?

单选题The announcement of the death of their leader caused thereafter a feeling of great despair to ______ their lives.

单选题Cancer cells destroy not only all rival cells, in their ruthless biological warfare, but also destroy the larger organization—the body itself—signing their own suicide warrant.

单选题It is now common for physically disabled individuals to receive the {{U}}bulk{{/U}} of their education in regular school programs.

单选题The passage is primarily concerned with ______.

单选题______ nutrition can help to slow the aging process--a balanced, healthy whole food diet is essential.

单选题Captain Jones ______ that five bullets came from Hoffman's gun and that he had the shells of those bullets with him.