问题 填空题

使用电火花计时器来分析物体运动情况的实验中:

(1)在如下基本步骤中,正确的排列顺序为______.

A.把电火花计时器固定在桌子上B.安好纸带C.松开纸带让物体带着纸带运动

D.接通220V交流电源E.按下脉冲输出开关,进行打点

(2)在安放纸带时,要检查墨粉纸盘是否已经正确地套在______上,还要检查______是否夹在两纸带之间.

答案

实验步骤要遵循先安装器材后进行实验的原则进行,注意实验中为了使打点稳定后再进行实验,同时为了提高纸带的利用率,尽量将纸带上打满点,要先接通电源后释放纸带.

故答案为:ABDEC.

在安放纸带时,要检查墨粉纸盘是否已经正确地套在纸盘轴上,还要检查墨粉纸盘是否夹在两纸带之间.

故答案为:纸盘轴;墨粉纸盘

选择题
阅读理解

C

  A scientist who developed a way to calculate(计算) how much water is used in the produciton of anything form a cup of coffee to a hamburger was awarded the 2008 Stockholm Water Prize.

  Professor John Anthony Allan of the University of London in Britain won the award for introducing the idea of "virtual water(虚拟水)",a calculation method that has changed the nature of trade policy and research.

  Allan has written seven books and published more than 100 papers.

  The Stockholm International Water Institute said this idea is now embedded(埋藏) in the production of foods and industrial products.The institute said Allan's work had made a big effect on global trade policy and research,especially in water - scarce(缺水) regions.

  "The improved understanding of trade and water management issues on local,regional and global scales are of the highest value for the successsful and sustainable(可持续的) use of water resources,"it said.

  "People do not only use water when they drink it or take a shower,"the institute said. "Behind the morning cup of coffee,there are 140 liters of water that was used to grow,produce,package and ship the beans."That is about as much water as a person in England uses on average for all daily drinking and household needs.

  "For a single hamburger,about 2,400 liters of water are needed.In te USA ,the average person uses nearly 7,000 liters of virtual water every day" It said that was more than three times the average use of a Chinese person.

  64.Allan was awarded the prize because ______.

   A.he wrote seven books on trade policy

   B.he published more than 100 papers on water management

   C.he found a new kind of water in water - scarce areas

   D.he came up with the idea of virtual water

  65.Which of the following is TRUE according to the passage?

   A.The average American uses about 7,000 liters of water a day.

   B.The average Chinese uses nearly 2,300 liters of virtual water a day.

   C.An Englishman usually drinks about 140 liters of coffee a day.

   D.A hamburger usually contains about 2,400 liters of water.

  66.What effect does the idea of virtual water have?

   A.It helps us realize the importance of trade.

   B.It helps people do successful business.

   C.It helps us make use of water scientifically.

   D.It tells us how much water we use a day.

  67.What does the underlined word "it" in the last paragraph refer to?

   A.The University of London.

   B.The calculation method.

   C.The Stockholm International Water Institute.

   D.The trade policy and research.