Passage 2Question 8 to 10 are based on the passage you have just heard.[听力原文]8-10In ancient Egypt, as everywhere, throwing stones was a favourite children’s game. But a badly thrown rock could hurt a child. Looking for something less dangerous to throw. what the Egyptians made were probably the first balls.At first, balls were made of grass or leaves held together by vines. Later they were made of pieces of animal skin sewed together and stuffed with feathers or hay.Even though the Egyptians like fighting, they found time for peaceful games. Before long they had developed a number of tall games, each with its own set of rules. Perhaps they played ball more for instruction than for fun. Ball playing was thought of mainly as a way to teach each young man the speed and skill he would need for war. What is the reason for ancient people to play bail()
A. To get fun.
B. To fight.
C. To learn speed and skill.
D. To learn how to be a soldier.
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张力性气胸、胸腔闭式引流后,排出大量气体,病人呼吸困难不见好转,最大可能是由于
A. 大气管断裂
B. 肺挫伤
C. 食管破裂
D. 引流层周围进气
E. 肠疝并有消化道穿孔
某工程项目的业主与监理单位签订了施工阶段监理合同,与承包方签订了工程施工合同。施工合同规定:设备由业主供应,其他建筑材料由承包方采购。 施工过程中,承包方未经监理工程师同意,订购了一批钢材,钢材运抵施工现场后,监理工程师进行了检验,检验中监理工程师发现承包方未能提交该批材料的产品合格证、质量保证书和材质化验单,且这批钢材外观质量不好。 业主经与设计单位商定,对主要装饰材料指定了材质、颜色和样品,并向承包方推荐厂家,承包方与生产厂家签订了购货合同。厂家将石料按合同采购量送达现场,进场时经检查,该批材料颜色有部分不符合要求,监理工程师通知承包方该批材料不得使用,承包方要求厂家将不符合要求的石料退换,厂家要求承包方支付退货运费,承包方不同意支付,厂家要求业主在应付给承包方工程款中扣除上述费用。 在施工过程中,施工单位发现某处图纸施工难度很大,需要进行工程变更,随与设计单位口头协商后,监理工程师监督承包单位执行协商后的方案,并做了现场详细的记录和检查验收。 【问题】
Although the United States has been shaped by continual waves of immigrants, Americans have often viewed immigration as a problem. Established Americans often look down on new immigrants. Despite such tensions, economic needs have always forced Americans to seek immigrants as laborers and settlers, and economic opportunities have appealed to foreigners. The vast majority of immigrants to the United States have come in search of jobs and the chance to create a better life for themselves and their families.In all of American history, less than 10 percent of immigrants have come for political or religious reasons.Economic immigrants from Europe, Asia, and Latin America have come to the United States voluntarily. Others, most African Americans, were involuntarily transported to North America to do forced labor or to be sold as slaves. Regardless of the reasons they come to the United States, new immigrants typically work in labor-intensive, low-paying, and dangerous jobs--occupations that most other Americans avoid.Although immigrants are expected to absorb the beliefs and standards of the dominant society, most immigrant groups try to maintain their own cultural tradition, language, and religious practices. Some groups, such as the Huguenots (French Protestants) who immigrated during the colonial period, assimilated (同化)within one or two generations. Others, such as the German and Irish immigrants of the 19th century, still maintain some aspects of their traditional cultures.Traditionally the United States has been described as a melting pot, a place where the previous identities of each immigrant group are melted down to create an integrated, uniform society. From the article we can induce()
A. the United States is a nation who hates immigrants
B. the United States is a nation who needs immigrants
C. the United States is a nation of immigrants
D. the United States is a nation who is a melting pot
An airplane flies because its wings push down on the air flowing past them, and in reaction, the air pushes up on the wings. When an airplane is level or rising, the front edges of its wings ride higher than the rear edges. The angle the wings make with the horizontal is called the angle of attack. As the wings move through the air, this angle causes them to push air flowing under them downward. A sleeper angle of attack will cause the wings to push more air downward. The third law of motion voiced by English physicist Isaac Newton states that every action produces an equal and opposite reaction. In this case, the wings pushing air downward is the action, and the air pushing the wings upward is the reaction. This causes lift, the upward force on the plane, Lift is often explained using Bernoulli’s principle, which states that, in some circumstances, a faster moving fluid(流体) (such as air)will have a lower pressure than a slower moving fluid. The air on the top of an airplane wing is at a lower pressure than the air underneath the wing, but this is an effect of lift, not its cause.Lift is one of the four primary forces acting upon an airplane. The others are weight, thrust, and drag. Weight is the force that offsets lilt. because it acts in the opposite direction. The weight of the airplane must be overcome by the lift produced by the wings, if an airplane weighs 4.5 metric tons, then the lift produced by its wings must be greater than 4.5 metric tons in order for the airplane to leave the ground. Designing a wing that is powerful enough to lift an airplane off the ground, and yet efficient enough to fly at high speeds over extremely long distances, is one of the marvels of aircraft technology. In the last sentence "Designing a wing that is powerful enough to lift an airplane off the ground, and yet efficient enough to fly at high speeds over extremely long distances, is one of the marvels of aircraft technology.", what is the meaning of the word "marvel"