B
【文章导读】本文是一篇趣味科学实验指南，详细介绍了实验所需材料、操作步骤以及实验现象和原理，强调了空气压力在实验中的作用。
Hi, young scientist! Are you ready for some fun with science? Doing experiments is so interesting and it helps us question what we learn, think deeply, and create new ideas. Here is an easy and fun experiment about air pressure(压力) that you can do at home or school. Let's have a try!
What do we need?
①a glass ②a piece of cardboard(硬纸板) ③some clean water
How can we do it?
Step One: Fill a glass with water.
Step Two: Put a piece of cardboard over the glass.
Step Three: Turn the glass over as quickly as possible.
Step Four: Hold your hand on the cardboard for a few seconds.
Step Five: Remove(移走) your hand from underneath of the glass.
What will happen?
The glass of water is upside down, but the water stays in the glass.
Why does this experiment happen?
This is because air pressure pushes the cardboard onto the glass. There is more air outside the glass than inside, so there is more air pressure outside than inside.
()1. How many kinds of things do you need to do this experiment?
A. Two.
B. Three.
C. Four.
D. Five.
()2. What is the second step of the experiment?
A. Put a piece of cardboard over the glass.
B. Turn the glass over as quickly as possible.
C. Hold your hand on the cardboard for a while.
D. Remove your hand from underneath of the glass.
()3. What makes the piece of cardboard onto the glass?
A. The hand.
B. Air pressure.
C. Clear water.
D. The glass.
()4. What is the purpose(目的) of the text?
A. To help students develop interest in science.
B. To let students know more about water facts.
C. To talk about the importance of saving water.
D. To call on people to take part in experiments.

B. 1.B 2.A 3.B 4.A
【解析】1. 细节理解题。短文“What do we need”中列出了实验所需的三种材料：玻璃杯、硬纸板和清水。故选B。 2. 细节理解题。根据短文列出的实验步骤可知第二步应选A。 3. 细节理解题。根据短文最后一段解释的实验原理可知是空气压力推动硬纸板紧贴在玻璃杯上。故选B。 4. 主旨大意题。根据短文第一段可知有趣的实验是为了培养学生对科学的兴趣。故选A。

【分析】
本题是一篇结合趣味科学实验的英语阅读理解题，包含4道选择题，考查细节理解与主旨大意。解题思路为：先通读全文，明确文章介绍空气压力实验的材料、步骤、现象及原理；再针对每个问题，回到原文定位对应信息，分析选项后得出答案。
【解析】
1. 细节理解题。根据文中“What do we need?”部分，实验所需材料为玻璃杯、硬纸板、清水，共3种，对应选项B。
2. 细节理解题。根据实验步骤Step Two: Put a piece of cardboard over the glass，对应选项A。
3. 细节理解题。根据最后一段“This is because air pressure pushes the cardboard onto the glass.”，可知是空气压力让硬纸板紧贴玻璃杯，对应选项B。
4. 主旨大意题。根据第一段“Are you ready for some fun with science? Doing experiments is so interesting and it helps us question what we learn...”，可知文章目的是培养学生对科学的兴趣，对应选项A。
【答案】
1.B 2.A 3.B 4.A
【知识点】
英语阅读理解、细节理解题、主旨大意题
【点评】
本题以科学实验为载体，既考查英语阅读信息提取能力，又涉及基础科学常识，题目设置贴合学生认知，难度适中。
【难度系数】
0.6