题干

原理Cr2O72+CH3CH2OH+H++H2O→[Cr(H2O)6]3++CH3COOH(未配平)可用于检测司机是否酒后驾驶,下列说法正确的是(   )

A:消耗1 mol CH3CH2OH时转移电子的物质的量为4mol

B:1mol/L CH3COOH溶液中含有σ键的数目为7NA

C:H2F+、NH2、H2S、CH4均与H2O互为等电子体

D:在配合物Cr(H2O)63+中,H,O原子与中心离子Cr3+形成配位键

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A

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    My mother is a diligent and kind woman. She is very busy from morning till night. As a teacher, she works hard.____ Both my brother and I love her dearly as she loves us.

    My mother has been teaching math at a middle school in my hometown. She goes to work early in the morning and does not return home until late in the afternoon. ____ She treats them with patience and teaches them well. For her excellent quality and very good teaching results, she has been elected as a model teacher several times.

    ____ Every day, when she comes back home from work, she sets about doing housework, sweeping the living room and bedrooms or cleaning the furniture, and putting everything in good order. She seems to be busy all the time. As she has been very busy working every day, she looks older than her age. But she looks as cheerful and happy as ever. Mother never buys expensive dresses for herself, but she often buys some inexpensive but high quality clothes for us.____She just eats a plain meal outside when she is too busy to cook herself. She lives a busy yet simple life, without any complaints.

    Often she says to us, “Work while you work, and play while you play. That is the way to be happy and gay. If you do not work, you will become lazy and be of no use to society”. What a piece of good advice this is! ____This advice of hers will always serve as a guide to my behavior. My mother is great indeed, and I always feel proud of her.

A. She enjoys listening to classical music.

B. As a mother, she takes good care of us and gives us every comfort.

C. She loves her students and cares for them.

D. She never goes to expensive restaurants to enjoy meals.

E. My mother is hard-working and never wastes money.

F. I never forget it and always bear it in my mind.

G. Can you tell us something about your mother?