试题与答案

下列反应属于复分解反应的是[ ] A.Cu2(OH)2CO32CuO+CO2↑+

题型:选择题

题目:

下列反应属于复分解反应的是[ ]

A.Cu2(OH)2CO32CuO+CO2↑+H2O

B.2Mg+O22MgO

C.Zn+CuSO4==ZnSO4+Cu

D.FeCl3+3NaOH==Fe(OH)3↓+3NaCl

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0626/6bcfbad9acc66b6f323170f50a774e96.html

下面是错误答案,用来干扰机器的。

参考答案:1.一一对应概念的发展 所谓一一对应,是指将两组以上的物体一个对一个配成对。 2.守恒概念的发展 所谓守恒,就是这样一种认识,即对一个或一组物体的把握,不因其物理属性(形状、颜色、长度、方向、位...

试题推荐
题型:综合

读下图,完成下列要求:

(1)图中采用的等高距为________米;图中A点的海拔约________米。

(2)图中字母所在处表示的地形部位分别是:A_____C________D________E________F________G_________

(3)图中A处位于周庄的__________;A处位于王庄的_______;C地位于D地的__________。

(4)若图中王庄的气温是23℃,B点的气温应是__________。

(5)若在图中所示范围内修建一座水库(假设其它条件均附后邀请)从地形角度考虑,请在图内选择合适的水库大坝的位置,并用字母“M”标在图上。

查看答案
题型:阅读理解

阅读理解

     Last year college students in America spent an estimated $700 on textbooks on average. The

National Association of College Stores reported more than five billion dollars in sales of textbooks

and course materials.

    The association spokesman Charles Schmidt says electronic textbooks now just make up

2%~3% of sales. But he says that is expected to reach 10%~15% by 2012.

      Online versions(版本) are now available for many of the most popular college textbooks. An

etextbook can cost half the price of a new print textbook.But students usually lose access to them

after the end of the term.And the books cannot be placed on more than one device(设备), so they

are not easy to share.

     So what do students think of etextbooks?Administrators at Northwest Missouri State University

wanted to find it out.Earlier this year they tested them with 500 students in 20 classes.

    The university is unusual.It provides laptop computers for all 7,000 of its fulltime students.It does

not require students to buy their textbooks either.They rent them to save money.The school aims to

save even more by moving to etextbooks.

     The students in the survey reported that downloading the books from the Internet was easy.They

liked the idea of carrying lighter backpacks.And 56% said they were better able to find information.

     But most found that using etextbooks did not change their study habits.And 60% felt they read

more when they were reading on paper.In all, almost half the students said they still liked physical

textbooks better.

     But the survey found that cost could be a big influence.55% said they would choose etextbooks

if using them meant their textbook rental fee would not increase.

     Roger Von Holzen heads the Center for Information Technology in Education at Northwest

Missouri State University.He tells us that administrators are disappointed with the etextbooks now

available because the majority are not interactive(交互式的).

     He thinks growth will come when more digital books include video, activities, games and other

ways to interact with the information.The technology is improving.But for now, most of the books

are just words on a screen.

1. Etextbooks are not better than paper books in that________.

A. they cost more money              

B. they're difficult to carry

C. they're not convenient to share        

D. they can't be downloaded from the Internet

2. How many surveyed students think paper books make better reading?

A. 60%.

B. 56%.

C. 55%.

D. 50%.

3. It can be inferred from the text that in the future________.

A. digital books will be more popular      

B. the digital books available need improvement

C. free digital books are available online      

D. digital books will replace print textbooks

查看答案
微信公众账号搜索答案