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问题 解答题

甲、乙、丙三名同学一起玩掷硬币的游戏，游戏规定：将两枚硬币随意掷出，若两个都为正（即字面向上），则甲得2分；若一正一反，则乙得1分；若两个都为反，则丙得2分，谁先累计到10分，谁获胜，这个游戏公平吗请说出为什么．

答案

这个游戏公平．因为每次甲胜的概率为

1
4
，平均每次甲得的分数为
1
4
×2=
1
2
分．乙胜的概率为
1
2
，平均每次乙得分为
1
2
×1=
1
2
分．丙胜的概率为
1
4
，平均每次丙得分为
1
4
×2=
1
2
分．因此平均每次三人得分相同，所以此游戏公平．

阅读理解

阅读理解。

Dear Wu Qian,      

     Thank you very much for your letter. You want to know about my favorite sport and instruments. Now

  I tell you. I like playing basketball very much. And I like volleyball and ping-pong. Playing basketball is

 my favorite instrument is piao. I play the piao every weekend. What about you? What's your favorite

 sport? Do you like to play the piano? Who's your favorite player? Please write and tell me. 

                                                                                                                                  Yours,

                                                                                                                                 Han Mei

1. The letter is from _____.

    A. Han Mei  

    B. Wu Qian  

    C. Lucy    

    D. Bob

2. Han Mei's favorite sport is _____.

    A. swimming  

    B. playing basketball  

    C. running    

    D. playing volleyball

3. Han Mei is good at _____.

    A. dancing    

    B. singing    

    C. painting    

    D. swimming

4. Han Mei wants to know _____.

    A. how old Wu Qian is

    B. What Wu Qian has  

    C. what Wu Qian's favorite sport is  

    D. where Wu Qian has

5.The letter is to _____.

    A. a teacher    

    B. Mary    

    C. Han Mei    

    D. Wu Qian
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单项选择题

将多台PC机组成以太局域网时，需要一些连接设备和传输介质。下面哪个设备或介质是不需要用到的？

A． 网卡

B． 集线器

C． 网线和接头

D． 调制解调器
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