测定砂浆凝结时间的压力表测量精度应为()NA.0.1 B.0.3 C.0.5 D.0

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问题:

测定砂浆凝结时间的压力表测量精度应为()N

A.0.1

B.0.3

C.0.5

D.0.6

考点:混凝土试验员考试混凝土基础知识及配合比设计混凝土基础知识及配合比设计题库
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基因工程的实施包括四个必要条件:()、()、()和()。

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油酸酒精溶液的浓度为每1 000mL油酸酒精溶液中有油酸0.6mL,用滴管向量筒内滴50滴上述溶液,量筒中的溶液体积增加1mL。若把一滴这样的溶液滴入盛水的浅盘中,由于酒精溶于水,油酸在水面展开,稳定后形成的一层单分子油膜的形状如图所示。

(1)若每一小方格的边长为30mm,则油酸薄膜的面积为________m2

(2)每一滴油酸酒精溶液含有纯油酸的体积为________m3

(3)根据上述数据,估算出油酸分子的直径为________m。

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下列哪个解剖结构不属于呼吸系统?()

A.气管

B.食管

C.鼻

D.咽

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What is a knowledge worker Knowledge workers are people who routinely use a computer in their work to enhance their productivity. She or he is the critical component in a computer system. A computer system is made up of people, using data and procedures to work with software and hardware components. It takes all five working together to produce results. Knowledge workers are white-collar professionals from many walks of life who have the following characteristics.

They understand how to use a personal computer.

They know how to work with computer-based information.

They understand how the computer benefits their work and the business.

They regard the computer as a productivity tool.

Knowledge workers may be employed in a company of any size, large or small, at a wide range of tasks. They may be self-employed, working in their own office or at home. They may be sales representatives or managers who travel with a portable computer. Students are knowledge workers as well. Many of you may be preparing for a career in knowledge work in office automation, public relations, account supervision, social work, management, or a number of other occupations.

Today, there are over 70 million knowledge workers in the United States, who generate nearly 2 trillion pieces of paper each year. These knowledge workers work 10 hours per week more than they did 10 years ago, and create over 15 billion new pieces of paper a year. According to a survey conducted by Industry Week magazine in 1990, 39 percent of U. S. management-level knowledge workers say paperwork is a problem. Further, USA Today reported in 1991 that the average knowledge worker has 36 hours of work stacked up on the desk. Clearly, the computer as a productivity tool must play an ever more important role in knowledge work and knowledge work itself is steadily assuming larger proportions. According to several worldwide studies, urban centers in Canada, the United States, Europe, and other developed areas are increasingly using computer technology and thus evolving knowledge-based cities. These knowledge-based cities are characterized by. (1) a concentration of scientists and engineers, (2) business, university, and governmental research activities, (3) a high degree of interaction between individuals and the various institutions, and (4) a positive image that attracts college graduates to knowledge work. Clearly, the decade of the 1990s and the new millennium that follows are an exciting time for knowledge work.

Which of the following can be called a knowledge worker().

A. A bank teller.

B. A sales representative.

C. A student.

D. All of the above.

题型:单项选择题

工业区、人口稠密区一般不宜使用()

A、重锤震源

B、可控震源

C、非炸药震源

D、炸药震源

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