为了保护数据库,必须在几个层次上采取安全措施,以下( )不是其中之一。 A.物理层

题型:单项选择题

问题:

为了保护数据库,必须在几个层次上采取安全措施,以下( )不是其中之一。

A.物理层
B.操作系统层
C.数据链路层
D.网络层

考点:计算机等级考试数据库技术三级数据库技术笔试
题型:单项选择题

消防人员到达建筑物倒塌事故现场后,开展侦察检测的主要方面有()。

A、利用生命探测器搜寻遇险和被困人员

B、利用检测仪器检测事故现场可燃气体的浓度

C、查明周围建筑物的安全情况

D、查明外围人员数量

E、利用搜救犬等搜寻遇险和被困人员

题型:单项选择题

胃酸过多可服用Al(OH)3胶囊或NaHCO3粉剂等进行治疗,试写出它们分别和胃酸的主要成分HCl反应的离子方程式:                                               、

                                            ,但如果胃部已出现溃疡,则不可服用上述两种制剂中的            (填写物质的化学式) 。

题型:单项选择题

电网事故中,过电压等原因造成装置损坏,导致丧失保护功能的应可不予统计。

题型:单项选择题

Children are a relatively modem invention. Until a few hundred years ago they look like adult, wearing grown-up clothes and grown-up expressions, performing grown-up tasks. Children did not exist because the family as we know it had not evolved.
Children today not only exist; they have taken over in no place more than in America, and at no time more than now. It is always Kids Country here. Our civilization is child-centered, child-obsessed. A kid’s body is our physical ideal. In Kids Country we do not permit middle-aged. Thirty is promoted over 50, but 30 knows that soon his time to be overtaken will come.
We are the first society in which parents expect to learn from their children. Such a topsy-turvy situation has come to abort at least in part because, unlike the rest of the world, ours is an immigrant society, and for immigrants the only hope is in the kids. In the Old Country, that is, Europe, hope was in the father, and how much wealth he could accumulate and pass along to his children. In the growth pattern of America and its ever- expanding frontier, the young man was ever advised to GO WEST; the father was ever inheriting from his son. Kids Country may be the inevitable result.
Kids Country is not at all bad. America is the greatest country in the world to grow up in because it is Kids Country. We not only wear kids clothes and eat kids food; we dream kids dreams and make them come tree. It was, after all, a boys’ game to go to the moon.
If in the old days children did not exist, it seems equally true today that adults, as a class, have begun to disappear, condemning all of us to remain boys and girls forever, jogging and doing push-ups against eternity.

Which of the following statements is true

A.In America, 30 is equal to 50.

B.Thirty is no longer a young age and might soon be replaced by the younger people.

C.Thirty is already too old to survive in America.

D.Thirty becomes fifty too soon.

题型:单项选择题

解理总是平行于()发生的。

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