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问题 选择题

有①Na2CO3溶液 ②CH3COONa溶液 ③NaOH溶液各25mL，物质的量浓度均为 0.1mol·L-1，下列说法正确的是 [ ]

A．3种溶液pH的大小顺序是③>②>①

B．若将3种溶液稀释相同倍数，pH变化最大的是②

C．若分别加入25mL 0.1mol·L-1盐酸后，pH最大的是①

D．若3种溶液的pH均为9，则物质的量浓度的大小顺序是③>①>②

答案

答案：C

选择题

设a是最小的自然数，b是最大的负整数的相反数，c是绝对值最小的有理数，则a+b+c的值为[ ]

A．2

B．1

C．0

D．﹣1
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单项选择题

A few years ago I had an "aha!" moment regarding handwriting.
I had in my hand a sheet of paper with handwritten instructions on it for some sort of editorial task. It occurred at first that I did not recognize the handwriting, and then I realized whose it must be. I finally became aware of the fact that I had been working with this colleague for at least a year, maybe two, and yet I did not recognize her handwriting at that point.
It was a very important event in the computerization of life—a sign that the informal. Friendly communication of people working together in an office had changed from notes in pen to instant messages and emails. There was a time when our workdays were filled with little letters, and we recognized one another’s handwriting the way we knew voices or faces.
As a child visiting my father’s office, I was pleased to recognize, in little notes on the desks of his staff, the same handwriting I would see at home in the notes he would leave on the fridge—except that those notes were signed "dad" instead of "RFW".
All this has been on my mind because of the talk about The Rise and Fall of Handwriting, a book by Florey. Sire shows in her book a deep concern about the fall of handwriting and the failure of schools to teach children to write well, but many others argue that people in a digital age can’t be expected to learn to hold a pen.
I don’t buy it. I don’t want to see anyone cut off from the expressive, personal associations that a pen still promotes better than a digital keyboard does. For many a biographer, part of really getting to know their subjects is learning to read their handwriting.
What some people advocate is teaching one of the many attractive handwritings based on the handwriting of 16th century Italy. That may sound impossibly grand—as if they want kids to learn to draw by copying classical paintings. However, they have worked in many school systems.

The author’s father wrote notes in pen ______.

A．to both his family and his staff
B．to his family in small letters
C．to his family on the fridge
D．to his staff on the desk
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