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问题 单项选择题

负责定义数据库中信息的内容和结构，定义数据的安全性和完整性约束条件，监控数据库的使用和运行等工作的人员是

A．系统分析员

B．系统设计员

C．数据库管理员

D．应用程序员

答案

参考答案：C

探究题

图甲所示，是探究冰和蜡的熔化过程的实验装置。器材有：冰、蜡、热水瓶、试管、烧杯、铁架台（带铁夹）、搅棒、秒表、温度计、水。

（1）图乙是 ___________ （选填“冰”或“蜡”）的温度随时间变化的图象。图丙所示温度计显示的是蜡某时刻的温度，它的示数是 ___________ ℃。

（2）在冰和蜡熔化过程中，如果将试管从烧杯中拿出来，冰和蜡停止熔化。将试管放回烧杯后，冰和蜡又继续熔化。说明固体熔化时需要 ___________ （选填“吸收”或“放出”）热量。

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单项选择题

The history of African—Americans during the past 400 years is traditionally narrated (1) an ongoing struggle against (2) and indifference on the part of the American mainstream, and a struggle (3) as an upward movement is (4) toward ever more justice and opportunity.

Technology in and of (5) is not at fault; it’s much too simple to say that gunpowder or agricultural machinery or fiber optics (6) been the enemy of an (7) group of people. A certain machine is put (8) work in a certain way—the purpose (9) which it was designed. The people who design the machines are not intent on unleashing chaos; they are usually trying to (10) a task more quickly, cleanly, or cheaply, (11) the imperative of innovation and efficiency that has ruled Western civilization (12) the Renaissance.

Mastery of technology is second only (13) money as the true measure of accomplishment in this country, and it is very likely that by (14) this under-representation in the technological realm, and by not questioning and examining the folkways that have (15) it, blacks are allowing. (16) to be kept out of the mainstream once again. This time, however, they will be (17) from the greatest cash engine of the twenty-first century. Inner-city blacks in particular are in danger, and the beautiful suburbs (18) ring the decay of Hartford, shed the past and learn to exist without contemplating or encountering the tragedy of the inner city.

And blacks must change as well. The ways that (19) their ancestors through captivity and coming to freedom have begun to loose their utility. If blacks (20) to survive as full participants in this society, they have to understand what works now.

19（）

A.servicing

B.encircle

C.encircling

D.served
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