问题 填空题

一组数据7,3,x,2,1的平均数是3,则这组数据的中位数是______.

答案

这组数据的平均数=

1
5
(7+3+x+2+1)=
13+x
5
=3,

解得x=2,

这组数据重新排列是1,2,2,3,7,

∴这组数据的中位数是2.

故答案为:2.

单项选择题
阅读理解

阅读理解。

     An 80-year-old man was sitting on the sofa in his house along with his 45-year-old son.

Suddenly a crow (乌鸦) landed on their window.

     The father asked his son, "What is that?"

     The son replied, "That is a crow."

     After a few minutes, the father asked his son for the second time, "What is this?"

     The son said, "Father, I told you just now. It's a crow."

     After a little while, the father asked his son the same question for the third time, "What is

this?"

     This time, the son said to his father in a low and cold tone, "It's a crow, a crow."

     After a moment, the father yet again asked his son for the fourth time, "What is this?"

     This time his son shouted at his father, "Why do you keep asking me the same question

again and again? I have told you already, 'IT IS A CROW'. Are you not able to understand

this?"

     A minute later the father went to his room and came back with a diary, which he had kept

since his son was born. On opening a page, he asked his son to read that page.

     Today my little son aged three was sitting with me on the sofa when a crow suddenly landed

on the window edge. My son asked me 23 times what it was, and I replied him 23 times that it

was a crow. I hugged him lovingly each time he asked me the same question. I didn't at all feel

angry, but instead felt affection for my son.

     If your parents reach old age, do not look at them as a burden, but speak to them gently,

and be kind to them. From today say this aloud, "I want to see my parents happy forever. They

have cared for me ever since I was a little child. They have always showered me with love. I will

take care of my old parents in the best way no matter how they behave."

1. The writer mainly intends to ______.

A. tell us the function of a diary    

B. call on us to love our parents

C. teach us what a crow is          

D. introduce a pair of son and father

2. The underlined word "affection" probably means______.

A. puzzlement      

B. hatred(恨)  

C. worry        

D. love

3. We can infer that the father wrote that piece of diary at the age of ______.

A. eighty          

B. three      

C. thirty-eight    

D. forty-five

4. The old man brought out the diary, which he had kept since his son was born, because ______.

A. he forgot what had happened    

B. he would like his son to read it        

C. it could remind himself of the past

D. he wanted to find what a crow was