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Immediately after the Civil War, however, the diet began to change. (61) Rail transportation increased the supply and improved the quality of the milk that reached urban centers; cold storage and refrigerator cars made possible the greater consumption of fresh vegetalbes, fresh fruits, and fresh fish; and commercial canning extended the range of appetizing and healthy foods. Subsequently food statistics indicated an increased consumption of dairy products, fresh fruit, fresh vegetables, sugar and syrups, coffee, tea, cocoa, and spices. Decreased consumption was shown for meats, potatoes, and grain products. (62) By and large, the American diet continued to reflect a considerable reliance upon animal products, rather than on grains, which meant that a relatively large acreage was required to feed the American public. Whereas a grain and fish diet, such as in Japan, requires only a quarter of an acre high-yield cropland and no pasture per capita, the American diet requires about two and a half acres of cropland and ten acres of pasture per capita. Also it indicated a shift toward the so-called protective foods, toward those high in vitamins and proteins. (63) This change was greatly furthered by governmental food inspection (the Pure Food and Drug Act was passed in 1906), by the increasing use of mechanical refrigerators in the 1920’s and 1930’s and of freezers for frozen food during recent decades.In the years after World War I, a food revolution took place that was reminscent of the one that occurred after the Civil War. The output of the food-manufacturing industry quadrupled from 1900 to 1940. (64) In that interval, as we have mentioned earlier, home canning gave way to commercial canning, and the labor of housekeeping was lightened.Fortunately most of the major dietary changes that have taken place since the middle of the 19th century have resulted in better nutrition for the population. In part, these shifts have taken place because of a preference for new foods rather than old, but in part, they have been made because the new foods were advocated by nutritionists. Apparently American dietary customs were not so deeply ingrained as to prevent change in the interests of better health. (65) Possibly one factor that has contributed to the readiness of Americans to accept new foods or food preparations is the general familiarity most have with a variety of regional dishes coming from many different lands. Within a small area in New York City or San Francisco, one can find restaruants specializing in French, Italian, German, Turkish, Arabian, or Chinese cuisine. And at a Chinese restaurant in the United States the chef and waiter are as likely as not to be Oriental. In that interval, as we have mentioned earlier, home canning gave way to commercial canning, and the labor of housekeeping was lightened.

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Although the size of the workforce depends a great deal on the size of the total population, there are several other influences which also affect it. The age distribution of the total population has a very (21) effect on the available workforce. If the population has a high (22) of very young people or of (23) too old to work, then the available workforce would be lower than (24) there were an (25) spread age distribution. If the population grows raidly (26) natural increase, i.e., the number of births greatly (27) the number of deaths, then as a total population increases the proportion of the workforce (28) .Sometimes a population is described as aging, (29) means that the birth rate is either falling or growing very slowly, and as people retire (30) the workforce there are insufficient numbers of young people entering it to (31) those who are leaving it. The population is top heavy with older people. So the (32) of the population in the workforce declines when there is (33) a rapid increase in births or a falling birth rate.The age distribution of the population has several important effects on the economy. If the population is aging and there is an increase in the number of people retiring (34) a corresponding increase in the number entering the workforce, this raises the problem of the ability of the economy to provide a (35) level of social services to the retired group. If the (36) are to be cared (37) in special homes or hotels, finance must be (38) for that purpose. If the size of the workforce is small relative (39) the total population, then the government tax receipts are relatively low and either the government has less money available to it or the workforce members have to be (40) more heavily. 38().

A. feasible
B. available
C. practicable
D. tractable

阅读以下关于数据通信方面的叙述,回答问题1和问题2。 数据通讯是当前十分活跃与热门的计算机与信息技术的应用领域。某大型通信公司开发了其业务的主要支撑平台(也叫做“通信信息服务平台”)用于在全国与全球开展数据业务的需要。该平台是一个典型的Java技术应用于Internet的项目。马工程师提出在全系统中可以这样来用Java构架系统: (1)该系统可分为4层,分别是Browser、表示层、中间件层和数据层。 (2)表示层用Java中的Java Script来实现页面输出。 (3)中间件层用Java来实现CORBA,即实现Component(构件),主要实现业务逻辑的封装与复用。 (4)数据层主要是数据库和存储过程的实现。 在应用Java技术时,马工程师所采用的技术和策略可大致上归纳为以下5个方面: (1)使Java Script尽量简单,因为Java Script在系统中是放在服务器端执行的,该语言是通过一个解释器解释执行的,相对速度很慢,采用了两台HP前置机来运行Java Script,但是其运行速度还是不理想,所以在设计中把Java Script仅用来显示从中间件层所得到的数据,生成动态页面。在最初的设计中表示层(Java Script)曾承担了一些业务逻辑处理操作,导致效率不理想,因此,不得不尽量地减少Java Script的程序量。 (2)用Java实现CORBA时,应尽量考虑共享和复用。在本系统中,最初的设计是让Java在实现Component时,只是执行一些数据库表的操作,导致表示层的负载较大。后来,重新设计时,总结归纳了所有的Use Case,找出了其中可供共享和复用的接口,把相同的业务逻辑操作封装到一个接口中去。因为Java的执行效率比Java Script要高,因此提高了系统效率。 (3)由于在别的项目中,该公司曾大量地使用过Java中的JSP技术和Servlet技术。为了得到系统的一些执行速率的数据,采用了一个著名的压力测试软件——Load Runner来测试这两种技术的差别。测试表明:用JSP和Servlet完成同样的一个操作,并且保证是在相同的测试环境中(相同服务器、压力测试工作站与数据库环境),得到的测试数据却有着很大差别,JSP完成一个操作的平均执行时间大致会是Servlet程序的两倍。在一个企业级应用项目中,这可能是一个很关键的瓶颈。因此,我们得出的结论是:在可能的条件下,尽量地多使用Servlet。当然,与Servlet相比,JSP编程快速,修改方便,在访问量不是很大的应用场合下也是可以接受的。 (4)使用Java作为整体解决方案时,应尽量使用相同版本的JDK。在用Java作为编程语言的项目中,几乎大多要遇到“汉字”问题,即Java在没有经过转换的情况下,在输出汉字时,很可能会出现乱码。采用不同版本的JDK,解决的方案是不一样的,比如V1.1.2版本的 JDK和V1.3版本的JDK解决方法就会有一些不一样,把V1.2.2的Java程序放在v1.3的 JDK中,就不能顺利输出汉字了。其根本原因在于Java使用了Unicode编码,和中国的国标编码不一样。所以在这个意义上一些人竭力鼓吹的“一次编写,到处运行”似乎不一定能在所有的场合都行得通。 (5)使用Java时,应尽量遵从软件规范。在Java中有一个JVM的概念,即在Java虚拟机中使用了一个垃圾收集器,专门用来回收内存。但是该垃圾收集器在给编程人员带来方便的同时,也隐埋下了隐患。在程序设计中,并不能强制执行垃圾收集器,所以,开发人员不能确定某对象是否已释放,常常让编程人员养成依赖自动收集的坏习惯,因此我们要求:在 Try,Catch之后必须明确要求回收内存(当然,也只能是通知垃圾收集器来回收垃圾),这样可以有效地提高系统稳定性。 但是在使用Java作为解决方案时,也遇到很多头疼的问题,这些问题导致同时执行的并发性比较差,系统速度慢等等。归纳起来看,曾遇到过的主要具体的问题有: (1)用Java来实现CORBA中的Component,有时效率会比较低。 (2)用Java来建立数据库连接往往会比较慢。 (3)用JSP编程时容易导致系统信息的扩散。比如,如果有黑客攻击一台运行JSP程序的服务器,他可以故意地输入一些非法字符或异常信息给JSP程序,于是程序执行将出现异常。这时,就会在页面上打印出相应的错误信息。很不幸的是,这些信息极有可能暴露出这台服务器的JDK的版本号与路径信息等内容。这往往容易让黑客们有机可乘,有可能去抓住系统的漏洞。 [问题2] Java语言作为一种快捷、稳定的计.算机语言,开发基于因特网应用的项目大多是相当稳定和比较适用的。试用200字描述Java的应用前景。

Although the size of the workforce depends a great deal on the size of the total population, there are several other influences which also affect it. The age distribution of the total population has a very (21) effect on the available workforce. If the population has a high (22) of very young people or of (23) too old to work, then the available workforce would be lower than (24) there were an (25) spread age distribution. If the population grows raidly (26) natural increase, i.e., the number of births greatly (27) the number of deaths, then as a total population increases the proportion of the workforce (28) .Sometimes a population is described as aging, (29) means that the birth rate is either falling or growing very slowly, and as people retire (30) the workforce there are insufficient numbers of young people entering it to (31) those who are leaving it. The population is top heavy with older people. So the (32) of the population in the workforce declines when there is (33) a rapid increase in births or a falling birth rate.The age distribution of the population has several important effects on the economy. If the population is aging and there is an increase in the number of people retiring (34) a corresponding increase in the number entering the workforce, this raises the problem of the ability of the economy to provide a (35) level of social services to the retired group. If the (36) are to be cared (37) in special homes or hotels, finance must be (38) for that purpose. If the size of the workforce is small relative (39) the total population, then the government tax receipts are relatively low and either the government has less money available to it or the workforce members have to be (40) more heavily. 21().

A. little
B. marked
C. much
D. lot

The American educational system is based on the idea that as many people as possible should have access to as much education as possible. This fact alone distinguishes the U.S. system from most others, since in most others the objective is as much to screen people out as it is to keep them in. The U.S. system has no standardized examinations whose results systematically prevent students from going on to higher levels of study, as the British and many other systems do. Through secondary school and sometimes in post-secondary institutions as well, the American system tries to accommodate students even if their academic aspirations and aptitudes are not high, even if they are physically (and in some cases mentally) handicapped, and even if their native language is not English.The idea that as many people as possible should have as much eductaion as possible is, of course, an outcome of the Americans’ assumptions about equality among people. These assumptions do not mean that everyone has an equal opportunity to enter Harvard, Stanford, or other highly competitive post-secondary institutions. Admission to such institutions is generally restricted to the most academically able. The less able can usaully matriculate in a post-secondary institution, as the Malaysians observed, but one of lower quality.As of March 1982, only 3 percent of all Americans aged 25 or more had completed less than five years of elementary school. Seventy-one percent of those 25 or more had completed four years of high school or gone beyond that, and 17.7 percent had completed four or more year of post-secondary education. The median number of school years completed was 12.6. The number of tertiary (that is, post-secondary) students per 100,000 inhabitants was 5,355. Some contrasts: the number of tertiary students per 100,000 in the population was 4,006 in Canada, in no other country, according to UNESCO data, was the number of post-secondary students above 2,700 per 100,000. Korea had 2,696 tertiary students per 100,000 inhabitants; Japan, 2,030; the USSR, 1,970; Argentina, 1,890; HongKong, 1,353; Malaysia, 472; and Ethiopia, 48.Naturally, an educational system that retains as many people as the American system does is likely to enroll a broader range of students than a system that seeks to educate only the few who seem especially suited for academic work. In the American system, academic rigor tends to come later than it does in most other systems. In many instances, American students do not face truly demanding educational requirements until they seek a graduate (that is, post-baccalaureate) degree. Many other systems place heavy demands on students as early as their primary years - though college may be far less demanding, as is the case in Japan. According to the passage, the U.S. is different from most other countries in ().

A. culture
B. economy
C. history
D. educational system

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