问题 实验题

电影《闪闪的红星》中有这样一段故事:因红军主力战略转移,留下来坚持战斗的红军和赤卫队员被以胡汉三为首的国民党反动派围困在山上,时间一长,红军便缺少食盐。为了生存,红军派了十来岁的儿童团员潘冬子和一位老大爷下山买食盐,他们在乡亲们的帮助下很快就买到了食盐,并把食盐装进了竹筒做的茶壶中,扮作上山砍柴人来到了敌人设的关卡前,不料敌人盘查很严,冬子一看,知道提着竹筒是过不了关卡的;只见冬子眼睛一转,飞快的向河边跑去,不一会儿,冬子回来并顺利地通过了关卡。过了山坳,老大爷问冬子,你刚才去河边干什么,只见冬子解开棉袄,大爷用手一摸,湿润润的,一尝,咸的。大爷高兴的大叫起来:“冬子,你真聪明!” 请问:

(1)潘冬子把食盐藏在哪儿?                          

(2)回到山上的冬子得到固体食盐应进行的操作步骤依次为:                                 →                    

食盐是人们生活中不可缺少的调味剂,随着人们健康意识的提高,市场上出现了“加碘盐”、“叶绿素锌钠盐”、“低钠盐”等。某种低钠盐由NaCl、KCl、MgSO4三种物质组成,用它进行以下实验(假设每步均恰好完全反应)。

(3)写出步骤①的化学方程式:                                       

(4)若当x是AgNO3时,白色沉淀C是                       若当x是NaOH时,白色沉淀C是                     .

答案

(1)溶解后漂在棉袄上

(2)操作步骤依次为:溶解 → 过滤 → 蒸发结晶

(3)

(4)AgCl ; Mg(OH)2

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中的两项为多途选项。根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。选项中的两项为多途选项。

In many parts of the world, cars play an important role in daily life and many societies would not exist without them.  小题1: But this is the prediction made by a team of transport researchers who are taken seriously, not only by government but also by car manufacturers.

The Human Science and Advanced Technology Institute at Loughborough in the UK is part of an international research program.  小题2: That will mean much saving, no accidents and better use of roads. The super-intelligent car in the future will drive itself.  小题3: Instead, we will have a choice of cars and change them as frequently as we change our clothing.

According to Dr. David Davis, who leads the research team, these predictions are based on the rising cost of the car culture, which had blocked up our cities, polluted our air, and caused more deaths than both world wars put together.

Davis says, cars will be fitted with some intelligent devices(装置) to regulate(调节) the distance between one car and another.  小题4: computers are much safer drivers than people, so cars in a road train will be able to drive much closer together than cars driven by people.

By 2010, Dr. David Davis believes, car technology will give motorists a clear view of the road, whatever the weather conditions, by projecting an image of the road ahead on to the car’s windscreen.  小题5: Cars will be connected by an electronic tow bar to the car in front to form “road-trains”. “The front vehicle in such a train burns the normal amount.”says Davis. “but all the others in the train would burn about ten percent of the normal amount,  and so produce about ten percent of the pollution.”

A.The team there believes that by 2030 all cars will be computerized.

B.They believe that cars will become more important in 20 years.

C.And it will not be owned by one individual.

D.And by 2030, cars will travel in line, linked to each other electronically.E.So the idea that in 20 years’ time, no one will own cars may be hard to believe.

F.Every driver will use less fuel in the car he owns.

G.The car will automatically speed up, or slow down, to match the speed of the car in front.

单项选择题