小红和小明做游戏：他们在一个不透明的布袋中放入3个完全相同的_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题解答题

小红和小明做游戏：他们在一个不透明的布袋中放入3个完全相同的乒乓球，把它们分别标号为1，2，3，先由小红从袋中随机地摸出一个乒乓球然后放回，再由小明随机地摸出一个乒乓球．小红说：若摸出的两个球的数字的和是偶数，我获胜；否则，你获胜．

（1）请用树状图或列表法表示两人摸球可能出现的所有结果；

（2）若按小红说的规则进行游戏，这个游戏公平吗？请说明理由．

答案

（1）列表如下

	1	2	3
1	偶数	奇数	偶数
2	奇数	偶数	奇数
3	偶数	奇数	偶数

．

（2）不公平，因为共有9种等可能出现的结果，出现偶数的情况有5种，奇数有4种，即小红赢的概率为

5

9

，小明赢的概率为

4

9

，小红赢的概率大，所以不公平．

完形填空

Once in a small village faraway, there was a place known as the House of 1000 Mirrors.
A happy little dog learned about this place and decided to visit. When he arrived, he bounced (蹦跳) happily up the stairs to the doorway of the house. He looked through the doorway h his     lifted high and his tail wagging as fast as it could. To his great      , he found himself staring at 1000 other happy little dogs with their tails wagging just as fast as his. He smiled a great smile, and was      with 1000 great smiles. As he left the House, he thought to himself, “This is a very      place. I will come back and visit it       .”
In the same village, another little dog, who was not quite as      as the first one, decided to visit the house. He slowly climbed the stairs and hung his head low as he     into the door. When he saw the 1000 unfriendly-looking dogs staring back at him , he growled at them and was horrified to see 1000 little dogs growling back at him. As he left, he thought to himself, “That is a horrible place, and It will never go back      again.”
All the      in the world are mirrors. What kinds of reflectios do you see in the faces of people you     .

B．disappointment

C．the mirrors

D．make friends with

单项选择题

每年对每位职工的安全教育不少于（）小时。

A.10

B.20

C.30

D.40