题目

空气质量指数（Air Quality Index，简称AQI）是定量描述空气质量状况的质量状况的指数，空气质量按照AQI大小分为六级，0～50为优；51～100为良101﹣150为轻度污染；151﹣200为中度污染；201～300为重度污染；＞300为严重污染． 一环保人士记录去年某地某月10天的AQI的茎叶图如图． （Ⅰ）利用该样本估计该地本月空气质量优良（AQI≤100）的天数；（按这个月总共30天） （Ⅱ）将频率视为概率，从本月中随机抽取3天，记空气质量优良的天数为ξ，求ξ的概率分阅读下列短文，选出最佳选项。When I was about ten years old, I was walking down the street with my mother. She stopped to speak to Mr. Lee. I knew I could see Mr. Lee any time around the neighborhood, so I didn’t pay any attention to him. After we passed Mr. Lee, my mother stopped me and said something that has stuck with me from that day until now. She said seriously, “You let that be the last time you’ve ever walked by somebody and not opened up your mouth to speak, because even a dog will wag its tail when it passes you on the street.” Mother’s words sound simple, but it’s been a guidepost for me and the foundation of who I am.It’s not just something I believe in; it’s a way of life. I believe that every person deserves to feel someone acknowledge their presence, no matter how humble (卑微) they may be.At work, I always said hello to the founder of the company and ask him how our business was doing. But I also spoke to the people who cleaned the buildings and asked how their children were doing. After a few years of greeting the founder, I had the courage to ask him for a meeting. We had a great talk. At a certain point I asked him how far he thought I could go in his company. He said, “If you want to, you can get all the way to this seat.”I’ve become vice president, but it hasn’t changed the way I approach people. I still follow my mother’s advice. I speak to everyone I see, no matter where I am. I’ve learned that speaking to people creates a pathway into their world, and it allows them to come into mine, too.【1】What did the author do when he met Mr. Lee?A. He talked with somebody else.B. He was attracted by a dog.C. He greeted him politely.D. He ignored him.【2】What kind of person is the author’s mother?A. Optimistic. B. Kind-hearted. C. Strict. D. Open-minded.【3】How did the company founder reply to the author?A. He inspired him. B. He played a joke.C. He invited him to coffee. D. He gave him the seat.【4】What does the author think of saying hello to people?A. It’s a way to show sympathy to people.B. It can build connections with others.C. It’s a must to become a president.D. It can bring him what he wants.