问题 解答题

朝阳中学生物兴趣小组的同学,为进一步了解“酗酒危害人体健康”的知识,准备进行“酒精对水蚤心率的影响”的探究实验,于是大家查阅资料,并动手实践完成了整个探究过程,请回答:

(1)在该探究实验中兴趣小组同学提出的问题是:______.

(2)兴趣小组同学作出的假设是:______.

(3)该兴趣小组的同学设计了清水和体积分数分别为5%、10%、15%的酒精进行探究.该探究实验中设置清水的目的是:______. 实验操作中应控制好实验变量,本实验的变量是______.

答案

(1)根据生活现象和表格数据可知.提出的问题是:酒精对水蚤的心率有影响吗?

(2)对照实验的问题、假设和结论最好一致,因此可以假设:酒精对水蚤的心率有影响.

(3)对照实验又叫单一变量实验,只有一个量不同.其它量皆相同的实验.只有一个变量,这就是实验中所有探究的问题,是可以改变的量,即酒精溶液的浓度的不同.对照实验的对照组一般是条件正常的,变量没有变化的一组,实验组变量有变化的一组,因此设置清水这组,主要是起对照作用.

故答案为:

(1)酒精对水蚤的心率有影响吗?

(2)酒精对水蚤的心率有影响  (酒精对水蚤的心率没有影响)

(3)进行对照实验;酒精的体积分数(酒精的浓度)

阅读理解

Dear Friend,

The recent success of children's books has made the general public aware that there's a huge market out there.

And there's a growing need for new writers trained to create the $3 billion worth of children's books bought each year ... plus stories and articles needed by over 650 publishers of magazines for children and teenagers.

Who are these needed writers? They're ordinary folks like you and me.

But am I good enough?

I was once where you might be now. My thoughts of writing had been pushed down by self-doubt, and I didn't know where to turn for help.

Then, I accepted a free offer from the Institute to test my writing aptitude(潜能), and it turned out to be the inspiration I needed.

The promise that paid off

The Institute made the same promise to me that they will make to you, if you show basic writing ability:

You will complete at least one manuscript(手稿) suitable to hand in to a publisher by the time you finish our course.

I really didn't expect any publication before I finished the course, but that happened. I sold three stories. And I soon discovered that was not unusual at the Institute.

Since graduation, I have authored 34 nationally published children's books and over 300 stories and articles.

Free test and brochure

We offer a free aptitude test and will send you a copy of our brochure describing our recognized home-study courses on the basis of one-on-one training.

Realize your writing dream today. There's nothing sadder than a dream delayed until it fades forever.

Sincerely, 

Kristi Holl, Instructor

Institute of Children's Literature

小题1:From the first three paragraphs, we learn that_____.

A.children’s books are usually bestsellers

B.publishers are making $3 billion each year

C.magazines for teenagers have drawn public attention

D.there is a growing need for writers of children's books小题2:When finishing the course, you are promised to_____.

A.be a successful publisher

B.become a confident editor

C.finish one work for publication

D.get one story or article published小题3:Kristi Holl mentions her experience mainly to_____.

A.prove she is a good instructor

B.promote the writing program

C.give her advice on course preparation

D.show she sold more stories than article

单项选择题