问题 应用设计题

如何进行下列探究活动?在声源周围安装吸声材料是控制噪声的常用方法之一.在海绵和泡沫塑料这两种材料中,谁的吸声效果更好呢?请你设计一个实验回答这一问题.

要求:

(1)写出实验中用到的主要器材.

(2)简述实验过程.

(3)为了得到准确、可靠的结论,应控制哪些因素相同,比较什么现象就能得出结论.

答案

探究减弱噪声的一条途径:在声源出减弱噪声.

(1)实验器材:声源(如收音机等)、海绵、泡沫塑料、细线或胶带纸;

(2)实验过程:打开收音机,分别用海绵和泡沫塑料包裹该收音机,比较两种情况下听到声音响度的区别;

(3)两种材料的厚度,包裹收音机的方式,收音机的音量(响度),听者到收音机的距离等应保持相同;然后比较用海绵和泡沫塑料包裹该收音机的响度不同,即可得出结论.

单项选择题
阅读理解

Each week, this program explains the many meanings of English expressions. Today’s expressions include a very important word—“heart”. We will try to “get to the heart of the matter” to better understand the most important thing about words and their stories. So “take heart.” Have no fear about learning new expressions. Besides, popular English words can be fun. There is no need for a “heavy heart.” Such feelings of sadness would only “break my heart,” or make me feel unhappy and hopeless.

Now, let us suppose you and I were speaking freely about something private. We would be having a “heart to heart” discussion. I might speak from “the bottom of my heart, ” or say things honestly and truthfully. I might even “open up my heart” to you and tell you a secret. I would speak with “all my heart”.

When a person shares her feelings freely and openly like this, you might say she “wears her heart on her sleeve”. Her emotions are not protected.

If we had an honest discussion, both of us would know that the other person’s “heart is in the right place.” For example, I would know that you are a “kind-hearted” and well-meaning person. And, if you are a very good person, I would even say that you have “a heart of gold.” However, you might have a “change of heart” based on what I tell you. Our discussion might cause you to change the way you feel about something.

But, let us suppose you get angry over what I tell you. Or worse, you feel no sympathy or understanding for me or my situation. If this happens, I might think that you have a “heart of stone.” And, if you say something to make me frightened or worried, my “heart might stand still”.

小题1:If you are not so happy, you may feel that ________.

A.you “have a heart of stone”

B.you have to “take heart”

C.you “break you heart”

D.you “speak from the bottom of the heart”小题2:From the above passage we may see ________.

A.English words can all be used differently

B.some phrases do not have a fixed meaning

C.languages change with the time

D.the same word may have various meanings小题3:What is the passage trying to impress the readers?

A.To explain how “heart” is used in phrases.

B.To show the author’s perfect English.

C.To tell English learners to learn English in phrases.

D.To advertise an English course.小题4:Which of the following may serve as the best title of the passage?

A.A change of heart

B.Open up the heart of “heart”

C.Never let your heart stand still

D.Wear your heart on your sleeve