题目

（本小题满分12分） 已知集合，集合 ，集合    （1）求从集合中任取一个元素是（3，5）的概率；    （2）从集合中任取一个元素，求的概率；    （3）设为随机变量，，写出的分布列，并求。 答案：解：（1）设从中任取一个元素是（3，5）的事件为B，则        所以从中任取一个元素是（3，5）的概率为        （2）设从中任取一个元素，的事件为，有        （4，6），（6，4），（5，5），（5，6），（6，5），（6，6）        则P（C）=，所以从中任取一个元素的概率为 （3）可能取的语法填空阅读下面短文，按照句子结构的语法性和上下文的连贯性，在空格处填入一个恰当的词，或使用括号中词语的正确形式填空。An old carpenter（木匠）was ready to retire. His boss was sorry ___1.____ (see) the good worker go. He asked the carpenter ___2.____ he could build just one more house. The carpenter said yes, __3.___ his mind was not on the work any more.He used poor materials and worked on the house ____4.____(care). When the carpenter finished his work, the boss handed the front-door key to him. “This is your house,” he said, “a gift ___5.____ you.”____6.____ a surprise! If he had known he was building his own house, he would have done it differently. Now he had to live in the house he had poorly built.Think of ___7.___ (you) as the carpenter. Think about your life. ___8.___(build) it wisely. It is the only life you will ever build because life is a do-it-yourself project.Your life today is the result of your attitudes and choices you ___9.____(make) in the past. Your life tomorrow will be that of your attitudes and __10.____ (choice) you make today.