The author's main purpose in this article is to explain the______.

A . A. To give practical instruction for pruning a tree. B . B. To give a general description of pruning. C . C. To explain how trees develop diseases. D . D. To discuss different methods of pruning.

A．To change the behavior. or the thinking of its readers towards body-image. B．To convince people that it is harmful to be obsessed with superficial beauty. C．To persuade people to pursue more valuable things. D．To analyze why people pay so much attention to physical appearance.

A．explain how cold viruses are transmitted B．prove that a poor diet causes colds C．discuss the relationship between income and frequency of colds D．analyze the distribution of income among the people in the study

A．compare the consequences of the earthquakes that occurred in the U.S B．encourage civil engineers to make more extensive use of computers C．outline the history of the development of quake-resistant building materials D．report new developments in constructing quake- resistant building 此题为多项选择题。

A．To tell readers that horse appeared earlier than human being. B．To inform. us that horses can help us a lot. C．To introduce the history and characteristics of horses. D．To introduce the primitive horses to modern man.

A．To question Beverly Lauds opinions about spanking. B．To explain why parents should spank their kids. C．To compare two different views on spanking. D．To show the harmful effects of spanking.

A．explain why people have emotions B．show how people avoid the negative emotions C．explain what people should do before emotions D．define anti classify people's emotions

A．describe different types of medicine B．argue for the importance of medicine in health care C．show the crucial role religion plays in medical treatment D．compare the educational background of three different types of patients

A．to compare dog behaviors to chimp behavior B．to defend an idea C．to explore recent research on nonhuman self-awareness D．to evaluate a hypothesis 此题为多项选择题。

A．to stress the impact of the computer on society B．to explain the concept of computer literacy C．to illustrate the requirements for being competent citizens of tomorrow D．to emphasize that computer programming is an interesting and challenging job 此题为多项选择题。

A．to give advice on appropriate conduct for social occasions B．to provide ways of how to obtain information about people C．to call the reader's attention to the negative side of people's characters D．to discuss the various aspects of getting to know people

A．to persuade young children not to worry about criticism B．to stress the importance of positive reinforcement to children C．to discuss the skill of combining criticism with encouragement D．to teach young athletes how to avoid burnout

A．compare the consequences of the earthquakes that occurred in the U. S. B．outline the history of the development of quake- resistant building materials C．report new developments in constructing quake - resistant buildings D．encourage civil engineers to make more extensive use of computers

A．business in a free market economy B．business in a socialist economy C．the rights of businesses D．businesses' activities

A．To advise America to learn from its mistakes. B．To tell the readers how to look at WikiLeaks. C．To discuss how to deal with WikiLeaks. D．To show readers how to stick to their rules.

A．To review the impact of women becoming high earners. B．To contemplate the philosophy underlying individualism. C．To examine the trend of young people living alone. D．To stress the rebuilding of personal relationships.

A．To demonstrate so many people are concerned with philanthropy. B．To illustrate the manager's kindness. C．To show that such coincidences should have some hidden relationship which people can hardly explain in words. D．God or the cosmos had "synchronized watches" between the bookstore and the women's shelter. 此题为多项选择题。

A．discuss the problem of handling trash B．suggest ways to cope with traffic problems C．point out the disadvantage of hear traffic D．propose an alternative system of transportation

A．to indicate the way genetic testing works. B．to show the power of one's genetic makeup. C．to introduce genetic testing and its function. D．to reveal the influence of the environment on genes.

A．To remind people of the need of sustainable development. B．To suggest ways of ensuring sustainable food production. C．To advance new criteria for measuring farming progress. D．To urge people to rethink what sustainable agriculture is.

A．To show the inability of trains to compete with planes with respect to speed and convenience. B．To stress the influence of the automobile on America' s standard of convenience. C．To emphasize the function of travel agencies in market promotion. D．To illustrate the important role of persuasive communication in changing consumer attitudes.

A．To call on people to reduce carbon footprints. B．To offer tips on how to live a low-carbon life. C．To introduce the research on carbon footprints. D．To clear up misunderstandings about carbon emission.

A．tell us his own experience in life B．tell us how to find peace of mind C．tell us a happy trip he took with his children D．ask us to see things from both sides