在会计工作交接中，现金要根据会计账簿记录余额进行当面点交，如有短缺，可用白条抵库。(

（）既有检错功能又有纠错功能。

A．水平奇偶校验

B．垂直奇偶校验

C．海明校验

D．循环冗余校验

They often go to school ______ bus. [ ]

A. on    

B. take    

C. by    

D. in

关于防火卷帘的巡查要点，下列说法不正确的是()。

（A）防火卷帘是否处于正常升起状态 

（B）防火卷帘控制面板、门体是否完好无损 

（C）防火卷帘所对应的烟感、温感探头是否完好无损 

（D）防火卷帘下是否堆放杂物，只要不是可燃物就可以不管

At the beginning of the twentieth century, North American society held, as an ideal, the Nuclear Family. This presumably perfect residential, social, and economic unit consisted of an adult male, an adult female and their minor children. This structure was thought to be stable and long lasting.
However, a few decades later, the structure of that ideal family was being altered radically even while it was being touted as the structure to be aimed for. Popular magazines bemoaned the loss of the Nuclear Family and its replacement with inferior forms.
There are a number of factors that are acting in concert to apply pressure on the Nuclear Family and generate a variety of new structures. Some of these are:
The definition of marriage has changed somewhat in that few people now consider it to last "until death do us part". The concept of monogamy (the marriage of one man and one woman) has been modified to a form now referred to as serial monogamy (the marriage of one man and one woman at a time). This reflects the increasing equality of women and men in terms of economic advantage and the recognition that many women no longer depend on men for their survival. Women are acquiring independence and have become empowered to make their own choices. With this independence, the need to form a relationship with a man becomes less important. This change embodies the concept that the marriage is temporary and can be terminated by either partner at any time. Associated with this, of course, is the relaxation of the divorce laws and the significant reduction of the shame that had one time been attached to divorce.
The economy of North America has resulted in a two-tier system of a few rich who control most of the resources and a large portion of the population who control almost none of the resources. Because of this, many couples are forced to have both partners with full-time jobs outside the home. There are unintended byproducts of the need for a double income. The most important of these is the replacement of a mother-oriented socialization of children to a "stranger-oriented" socialization system reflected in the growth of the childcare industry. Also, either partner is financially able to end the marriage without significant hardship.
The combination of these changes will in the coming decades have a profound effect on the structure of the family of North America. As a result, the family will be a fluid, constantly changing structure with variable household arrangements as the norm.

In Paragraph 5, "two-tier system" means some ______.

A．men have many wives while others have none

B．people are very rich while others are very poor

C．people have too much work to do while others have nothing to do

D．people control others

中 * * 政治局2010年12月3日进行第二十四次集体学习时，胡 * * * * 在主持学习时强调，上海世博会的圆满成功，是在国际社会积极帮助下，全国各族人民大力支持、共同努力的成果，是上海广大干部群众顽强拼搏、真诚奉献的成果，是各地区各部门各单位齐心协力、密切配合的成果。上海世博会展示了中 * * 五千年灿烂文明，展示了新中国60年特别是改革开放30多年的辉煌成就，展示了我国各族人民为实现全面建设小康社会目标而团结奋斗的精神风貌，促进了我国同各国各地区经济文化交流，增进了我国人民同各国各地区人民相互了解和友谊。

胡 * * 强调，要认真吸收和运用上海世博会所展示的世界城市建设和管理的先进理念，坚持走中国特色城镇化道路，深入探索城市居住、生活、工作新模式，自觉统筹城乡一体化发展。

请运用政治常识“独立自主和平发展”相关内容对第一段材料予以分析说明。