问题 填空题

航天员拟在太空授课,准备进行标号为0,1,2,3,4,5的六项实验,向全世界人民普及太空知识,其中0号实验不能放在第一项,最后一项的标号小于它前面相邻一项的标号,则实验顺序的编排方法种数为     (用数字作答).

答案

300

题目分析:解:因为0号实验不能放在第一项,所以第一步是从1,2,3,4,5的五项实验任选一个放在第一项,有;

第二步:从剩下的五实验中任取三个放在第二、三、四项,有种不同的方法;

第三步:最后剩下两个实验,标号较大的放在第五项,较小的放在第六项,只有这一种方法;

根据分步乘法计数原理,实验顺序的编排方法种数为:

所以答案应填:300

单项选择题 A1型题
阅读理解

阅读理解。

     This booklet is designed to help you and your family plan for and survive a major earthquake. By

taking action to be prepared, you can lessen the impact of an earthquake on your family. Set aside

some emergency supplies, and teach your family what to do at home during and after a disaster. You

could be without help for up to 72 hours, so learn to cope for at least that long.

    Movement of the ground is seldom the actual cause of death or injury. Most casualties (意外) result

from partial building collapse and falling objects and debris, like toppling chimneys, falling bricks, ceiling

plaster, and light fixtures. Many of these conditions are easily preventable.

    Because earthquakes occur without warning, it's important to take steps now to prepare, so that you

know what you can do and how to respond-constructive, protective action is possible.

    Have on hand for Any Emergency- Ideas for Home, Workplace, and Car.

    Because you don't know where you will be when an earthquake occurs, prepare disaster supplies.

1. Who is the passage mainly written for? 

A. scientists      

B. parents      

C. the public      

D. teachers

2. How can we lessen the impact of an earthquake on our family?   

A. Stay at home.

B. Keep away from high buildings.

C. Learn some knowledge about the cause of earthquakes.

D. Know what to do in a disaster.

3. Which can be the best title of this passage? 

A. Are You Prepared for the Next Earthquake?

B. Earthquakes Occur Without Warning

C. How to Prevent Earthquakes

D. Cause of Earthquakes