问题 问答题 简答题

怎样保证电能计量装置的准确性?

答案

参考答案:

(1)供电企业应按规程规定的周期检验或检定、轮换计费电能表,并对电能计量装臵进行不定期检查。发现计量装臵失常时,应及时查明原因并按规定处理。

(2)发现因客户责任引起的电能计量装臵损坏,应礼貌地与客户分析损坏原因,由客户确认,并在工作单上签字。

实验题

在“观察水的沸腾”实验中

如图,是某同学选用温度计测小烧杯中水的初温的操作图,其中A是操作过程,B是读数过程。

 

①A图中操作的错误是                                         

②B图读数中的错误是                                         

③除了图中实验器材外,还需要的测量工具是                  

(2)该同学在做实验时,水的初温如图所示,其读数为_________,给水加热到水开始沸腾所用的时间过长,为了缩短水沸腾时间,你觉得应采取的方法是:___________________

或______________________________。

 

(3)图中(a)、(b)是某同学做观察水沸腾实验时看到气泡上升情况示意图,其中图_________一定是水在沸腾前的情况,当水温升至90℃时,每隔1min记录一次水温,4min后水开始沸腾,接着又观察记录了6min,然后移开酒精灯,停止加热,沸腾停止,记录数据如下表

时间t/min0123456789
温度T/℃90929496989898959898
该同学根据观察现象,分析数据,归纳有如下发现:

①水沸腾的时候,是在液体_______________同时进行的剧烈的汽化现象。

②从记录的数据看出,在某一次观察记录中有明显错误的是第_______min时的数据。

③停止加热,沸腾停止,说明沸腾过程需要     (填“吸”或“放”)热。 实验中你一定还有其他的发现,请写出其中任意一条:__________________________。

 

单项选择题

People can get emotional about immigration. Bill O’Reilly, a talk-show host, devoted a recent segment to the story of an illegal alien who got drunk and accidentally killed two attractive white girls with his car. If only he had been deported for previous misdemeanours, Mr. O’Reilly raged, those girls would still be alive. Another talk-show host, Geraldo Rivera, during an on-air shout-joust(争吵) with Mr. O’ Reilly, denounced his demagogic choice of story-angle as" a sin".

President George Bush tried again this week to bring a more rational tone to the debate. He urged the new Democratic Congress to revive the immigration reforms that the old Republican Congress killed last year. His proposal was broadly the same as before. He said he wanted to make it harder to enter America illegally, but easier to do so legally, and to offer a path to citizenship for the estimated 12m illegals who have already snuck in.

The first part faces few political hurdles and is already well under way. Mr. Bush expects to have doubled the number of Border Patrol agents by the end of next year. The new recruits are being trained. And to defend against the invading legions of would-be gardeners and hotel cleaners, the frontier is also equipped with high-tech military gizmos(小发明), such as unmanned spy planes with infra-red(红外) cameras. This may be having some effect. Mr. Bush boasted that the number of people caught sneaking over the border had fallen by nearly 30% this year.

And the controversial part of Mr. Bush’s immigration package--allowing more immigrants in and offering those already in America a chance to become legal -- is still just a plan. House Republicans squashed it last year. Mr. Bush senses a second chance with the new Democratic Congress, but Democrats, like Republicans, are split on the issue. Some, notably Ted Kennedy, think America should embrace hard- working migrants. Others fret that hard-working migrants will undercut the wages of the native-born.

Mr. Bush would like to see the pro-immigrant wings of both parties work together to give him a bill he can sign. The Senate is expected to squeeze in a debate next month. The administration is trying to entice law-and-order Republicans on board; a recent leaked memo talked of substantial fines for illegals before they can become legal and" much bigger" fines for employers who hire them before they do.

The biggest hurdle, however, may be the Democrats’ reluctance to co-operate with Mr. Bush. Some figure that, rather than letting their hated adversary share the credit for fixing the immigration system, they should stall until a Democrat is in the White House and then take it all. So there is a selfish as well as a moral argument for making a deal.

According to the text, Mr. Bush’s plan was opposed by ()

A. Bill O’Reilly

B. Geraldo Rivera

C. Ted Kennedy

D. the pro-immigrant wings