生产经营单位贯彻实施安全生产法,具体要抓好哪"六大保障"?:

题型:问答题 简答题

问题:

生产经营单位贯彻实施安全生产法,具体要抓好哪"六大保障"?:

考点:公司安全知识竞赛公司安全知识竞赛题库
题型:问答题 简答题

如图所示为电子显示仪器(如示波器)的核心部件.如图所示,左边部分为加速装置,阴极产生的热电子(电荷量为e,质量为m)由静止开始经加速电压μ1加速后,进入板长为l,间距为d,直流电压为μ2的偏转电场区域,偏转区域右侧为荧光屏,电子轰击荧光屏能够显示出光斑P.依据上述信息,求:

(l)电子离开加速电场时的速度大小;

(2)电子离开偏转电场时的速度与进入时速度的夹角的正切值;

(3)若把某时刻做为计时起点t=0,从该时刻起显示屏由静止开始向左做加速度为a的匀加速直线运动,试定量说明光斑在屏上的运动性质.

题型:问答题 简答题
设x,y是0,1,2,3,4,5中任意两个不同的数,那么复数x+yi恰好是纯虚数的概率为(  )
A.
1
6
B.
1
3
C.
1
5
D.
1
30
题型:问答题 简答题

In the future your automobile will run on water instead of gas! You will be able to buy a supercomputer that fits in your pocket! You might even drive a flying car!

Not all past predictions have been proved wrong. A few of them have been surprisingly accurate (正确无误). Some great thinkers predicted the arrival of the credit card, the fax machine and even the internet years before they happened. But for each prediction that has come true, some others have missed by a mile. Many of these predictions didn’t consider how people would want to use the technology or if people really needed it in their lives or not. Let’s look at some predictions from the not-too-distant past.

Robot Helpers

Where’s the robot in my kitchen? Nowhere, of course. And he’s probably not coming anytime soon. Robots do exist today, but mostly in factories and other working environments.

Back in the 1950s, however, people said that by now personal robots would be in most people’s homes.

So why hasn’t happened? Maybe because robots are still too expensive and clumsy(笨拙的). And probably the idea of robots cooking our dinners and washing our clothes is just too strange. At home we seem to be doing fine without them.

Telephones of tomorrow?

In 1964 an American company introduced the video telephone. They said by the year 2000 most people would have a video phone in their homes. But of course the idea hasn’t caught on yet.

Why? The technology worked fine, but it overlooked (忽略) something obvious: people desire for privacy. Would you want to have a video phone conversation with someone after you just stepped out of the shower?

Probably not — it could be uncomfortable! Just because technology doesn’t always mean people will want to use it.

And finally, how about that crazy prediction of the flying car? It’s not so crazy any more! But a flying car remains one of the most wonderful technology ideas to catch our imagination. Keep watching the news or perhaps the sky outside your window to see what the future will bring.

1. The passage mainly deals with______.

A. predictions that can catch our imagination

B. predictions that haven’t come true

C. new technology can benefit our life

D. predictions that have come true

2. According to the passage, which of the following statements is NOT true?

A. Technology doesn’t always mean people will want to use it.

B. Predictions don’t need to consider people’s practical use of the technology.

C. Not all the high-tech things people thought we’d be using by now are widely used.

D. High-tech things are not always convenient to people’s life.

3. Robot Helpers haven’t been used in most people’s homes because ______.

A. using the kind of robots at home is simply a waste of time and money

B. the kind of robots hasn’t been developed yet

C. people find it difficult to control the kind of robots

D. the kind of robots won’t bring people practical use

4. How does the writer find the flying car?

A. It is too difficult to imagine.        B. It is too crazy an idea to realize.

C. It is likely to appear in the future.    D. It has been the focus of the news.

题型:问答题 简答题

当井下发生垮面、冒顶事故,工作人员被堵在独头巷道或工作面内时,应怎样坚持待救和自救?

题型:问答题 简答题

机械拆解总包步骤分为哪几种?

更多题库