Question

18．A solar bag is a long plastic bag made from very thin plastic and colored black to take in solar energy．The heated air inside the bag causes the bag to float．Although the solar bag looks similar to a regular black trash bag，the key difference is the thickness of the plastic．A great science experiment might be testing bags of different thicknesses to see which one floats the highest!
Materials
v  Solar bag
v  Solar bag string
Notice that the bag is made out of a lightweight plastic material．Be careful when dealing with the bag since the pla stic will tear easily．
Carefully take the plastic bag from the packaging and hold one of the op en end of the bag．Tie this end with string．
The best time for a launch is in the cool morning．We have not had much success with a launch in the middle of a hot day．
Choose a proper place for the launch．Find a field clear of any buildings，trees and power lines．Choose a day to do the experiment when it is sunny and free of any wind．
Put the solar bag onto a soft surface like grass．Have one person hold the bag open as you begin to run around and fill the bag with air．
Fill the bag with air until about 2 feet remains without air so that you can hold it in your hand．Close the end and use a string to keep it on the ground．
The last part of the work is done by the sun．Gather around the giant bag but try not to touch it-sharp fingernails will easily break the thin plastic．Be careful!The outside of the bag also gets very hot to the touch．It's important to remember that it may t ake as long as ten minutes for the air inside to heat up enough to cause the bag to float．
25．What's the difference between a Solar Bag and a regular black trash bag？B
A．The weight．
B．The thickness．
C．The material．
D．The color．
26．The best time to launch a Solar Bag is inA．
A．a sunny cool morning without any wind
B．a sunny hot afternoon without any wind
C．a sunny cool morning with some wind
D．a sunny hot afternoon with some wind
27．A good place for a launch isB．
A．between buildings                    
B．in an open area
C．on top of a tree                       
D．near a power station．

Answer 1

分析 本文是一篇说明文．文章主要介绍了太阳能包的特点，以及我们如何做一个太阳能包．

解答 25．B  细节理解题   根据文章第一段第三句Although the solar bag looks similar to a regular black trash bag，the key difference is the thickness of the plastic．可知，与普通包的区别是塑料的厚度，故答案为B
26．A  细节理解题 根据文章The best time for a launch is in the cool morning．We have not had much success with a launch in the middle of a hot day．可知，使用太阳能包的最佳时间是无风的晴朗的凉爽早晨，故答案为A
27．B 细节理解题 根据文章Choose a proper place for the launch．Find a field clear of any buildings，trees and power lines．Choose a day to do the experiment when it is sunny and free of any wind．可知使用太阳能包最佳的地点是空旷的地方，故答案为B

点评 本文考查细节题为主，细节题可以在文章中直接找到与答案有关的信息？或是其变体．搜查信息在阅读中非常重要它包括理解作者在叙述某事时使用的具体事实、数据、图表等细节信息．在一篇短文里大部分篇幅都属于这类围绕主体展开的细节．做这类题一般采用寻读法？即先读题，然后带着问题快速阅读短文，找出与问题有关的词语或句子，再对相关部分进行分析对比，找出答案