不能设计为一个除尘系统的因素有哪些？

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

以下属于抽象行政行为的是：

A．某市拆迁管理办公室发布拆迁公告，要求某街道第30—39号房屋的居民在规定期限内搬迁

B．某县政府下发的关于该县如何进行拆迁补偿工作的文件

C．某市卫生局认为甲厂生产的医疗用品不合格，随即发出通知，要求该市所有医疗单位停止使用该厂所生产的医疗用品

D．市质量监督局制定的关于该市某种商品质量检验标准的规定

两种药物合用，能产生毒性反应或者副作用的配伍关系是（）

A.相须

B.相使

C.相反

D.相杀

E.相畏

表示特定区域的地形和所有建（构）筑物等布置以及邻近情况的平面图样是（）。

A.方案图

B.设计图

C.施工图

D.总布置图

电脱水变压器在使用过程中，（）必须可靠接地，以免发生生产事故。

A.火线

B.零线

C.相线

D.外壳