各变数倒数的算术平均数的倒数,即为这些变数的()。 A.算术平均数 B.几何平均数

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问题:

各变数倒数的算术平均数的倒数,即为这些变数的()。

A.算术平均数

B.几何平均数

C.调和平均数

D.中位数

考点:统计学生物统计附试验设计生物统计附试验设计题库
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一个小数,如果把它的小数点向右移动一位,就比原数多1.8,原来这个小数是(    )。

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鲜或冷秦岭细鳞鲑

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心源性哮喘与支气管哮喘的主要不同点是()。

A.有心血管疾病的病史

B.肺部有哮鸣音

C.双肺底可闻及湿啰音

D.咯粉红色泡沫痰

E.心脏扩大

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阅读理解。

                                                               Community College

     Here I am, a senior. After four years of high school, I have learned a lot of lessons. Some were

good and valuable. And I have also learned others just from growing up and being around other

teenagers.

     I started senior year with a 1.5 GPA (=grade point average平均分,相当于65%), which is not

even close to what I am capable of. The last three years I fooled around and cut lots of classes. Now,

I can easily say that it is the only thing in life that I regret. Next year I will watch most of my friends go

to college while I lost that chance. This does not mean that I am giving up on my dreams, but when I

started high school, my goal was to get great grades and go to a competitive college.

     At first I blamed the people around me for my bad experiences, but I've learned that it's my fault

when bad things happen. In the last three years I realized that I am the only one in control of myself.

While making my teachers and my peers the excuse for not wanting to go to class, I developed a huge

lying problem.

     If I could start over, I would in a heartbeat, but I can't, so instead of beating myself up, I try talking

to younger teenagers about the importance of doing well in school by explaining the situation I got myself

into. Community college looks like a great opportunity. I am looking forward to taking many credits and

receiving good grades. I see community college as a year to turn my life around. It's my ticket out of here

to wherever I want to go. I have another chance to make my future and I've promised myself I won't

mess up.

     We need to study history so we won't repeat our past; I've studied my personal history, and will

avoid my mistakes in the future. I am ready for the next task in life, the only question is, is it ready for

me?

1. The author takes the community college seriously because he wants to ________. 

A. show his ability to be one of the top students

B. prove that others did wrong to him before

C. improve himself and win others' respect

D. get the opportunity to apply for a good job

2. Which of the following is NOT the author's advice? 

A. To behave well at school is necessary.

B. Others should be blamed for our hard time.

C. Learn from past, don't make mistakes.

D. Be hopeful, choose community college.

3. From the passage, we know that the author is ________.

A. easygoing and hard working                        

B. confident and responsible

C. sensible and independent              

D. honest and ambitious

4. The underlined phrase "fooled around" in the second paragraph means "________". 

A. wasted time    

B. played tricks

C. made faces          

D. felt ashamed

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