下列离子方程式书写正确的是 A.氧化铝粉末投入NaOH溶液中: Al2O3+2O

题型:选择题

问题:

下列离子方程式书写正确的是

A.氧化铝粉末投入NaOH溶液中: Al2O3+2OH=2AlO2+H2

B.金属钠与水反应:2Na+2H2O=2Na+2OH+H2

C.碳酸钙与盐酸反应:CO32+2H=H2O+CO2

D.氢氧化钡溶液与稀硫酸反应:Ba2++SO42=BaSO4

考点:离子方程式
题型:选择题

在铜催化和加热的条件下,用苯甲醇制得了苯甲醛,同时还有氢气生成。分离出铜后,检验所得苯甲醛是否为纯净物可用的方法是        (   )

A.测蒸气的摩尔体积

B.能否使酸性高锰酸钾溶液褪色

C.测熔点

D.能否发生银镜反应

题型:选择题

Now many people move into cities in order to have their children __________.

A.better educate

B.receive well education

C.better educated

D.accept better education

题型:选择题


PASSAGE 1
To Err Is Human
by Lewis Thomas
Everyone must have had at least one personal experience with a computer error by this time. Bank balances are suddenly reported to have jumped from $379 into the millions, appeals for charitable contributions are mailed over and over to people with crazy sounding names at your address, department stores send the wrong bills, utility companies write that they’re turning everything off, that sort of thing. If you manage to get in touch with someone and complain, you then get instantaneously typed, guilty letters from the same computer, saying, "Our computer was in error, and an adjustment is being made in your account."
These are supposed to be the sheerest, blindest accidents. Mistakes are not believed to be the normal behavior of a good machine. If things go wrong, it must be a personal, human error, the result of fingering, tampering a button getting stuck, someone hitting the wrong key. The computer, at its normal best, is infallible.
I wonder whether this can be true. After all, the whole point of computers is that they represent an extension of the human brain, vastly improved upon but nonetheless human, superhuman maybe. A good computer can think clearly and quickly enough to beat you at chess, and some of them have even been programmed to write obscure verse. They can do anything we can do, and more besides.
It is not yet known whether a computer has its own consciousness, and it would be hard to find out about this. When you walk into one of those great halls now built for the huge machines, and standing listening, it is easy to imagine that the faint, distant noises are the sound of thinking, and the turning of the spools gives them the look of wild creatures rolling their eyes in the effort to concentrate, choking with information. But real thinking, and dreaming, are other matters. On the other hand, the evidence of something like an unconscious, equivalent to ours, are all around, in every mail. As extensions of the human brain, they have been constructed the same property of error, spontaneous, uncontrolled, and rich in possibilities.

The author uses his hypothesis that "computers represent an extension of the human brain" in order to indicate that

A.human beings are not infallible, nor are computers.

B.computers are bound to make as many errors as human beings.

C.errors made by computers can be avoided the same as human mistakes can be avoided.

D.computers are made by human beings and so are their errors.

题型:选择题

瓦斯治理工作体系是什么?

题型:选择题

空域管理的原则

更多题库