传说公元前202年，项羽逃到乌江边，看见张良用蚂蚁排成“霸王自刎乌江”六个大字，气得拔剑自刎．蚂蚁能按照人的设计围成大字，此行为是动物的（    ）

测量液体密度的仪器叫密度计，将其插入被测液体中，待静止后直接读取液面处的刻度值（图甲）．图乙和图丙的容器中是同一个自制的简易密度计，它是在木棒的一端缠绕一些铜丝做成的，将其放入盛有不同液体的两个烧杯中，它会竖直立在液体中，由图中现象可以判断

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下列行为中可能会直接造成土壤污染的是（  ）

    I had introduced myself to others by saying, “Hi, I am J's mother” or “A's mom” rather than my own name. Another mother 1 asked me, “And do you have a(n)2?”

    My friend 3 me a few days before. I kept on talking for five minutes about my 4 When I 5 she asked, “So, is there anything going on with 6?”

    At first, I didn't understand 7she was asking me that. Hadn't I just told her what was going on with me? But then I realized that 8 I said had actually been about myself. It was all about my kids. I love being a mom. The kids were my world.9 it was my kids' world, and I just lived in it and 10it didn't fall apart.

    The phone call with my friend made me 11 that I needed to start thinking about who else I am 12 being a mother. I realized that to be a good 13 I also had to be my own person-not just someone who only 14 to take care of other people.

    I joined a club and started doing some volunteer work. I took a writing class online. I am now a regular 15to several magazines and write a monthly blog. I don't make a lot of money by writing, but I feel more 16 as a person. I am 17 and growing, and that makes me more 18 and a better mother.

Now when I 19 myself, I say, “Hi, my name is Randi,” and it feels 20 to be me.

（Ⅰ）现要从中选派一人参加技能大赛，从这两名技工的测试成绩分析，派谁参加更合适；

（Ⅱ）若将频率视为概率，对选派参加技能大赛的技工在今后三次技能大赛的成绩进行预测，记这三次成绩中高于85分的次数为ξ，求ξ的分布列及数学期望．