论述菱形喷头布设方式的特点。_爱下问搜题

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问题问答题简答题

论述菱形喷头布设方式的特点。

答案

参考答案：

这种方式的组合适用于地形不规则、起伏较大的绿地。这种形式抗风能力强，喷洒均匀度高，而且喷头数量较少，节省投资。

单项选择题

对一个玩具，儿童既可按颜色归类，也可按形状归类，还可以按大小归类，说明这时儿童的认知水平已达到（　）。

A．感知运动阶段

B．前运算阶段

C．具体运算阶段

D．形式运算阶段

完形填空

“ Are you too stupid to do anything right？”These words—said by a woman to a little boy who was obviously her son—were spoken   21   he had walked away from her．They boy returned, his eyes down-cast.
Not a   22    moment, perhaps,   23    small moments sometimes last a very long time．And a few words—though they mean   24   at the time to the people who say them—can have great   25   .
I recently heard a story from a man named Malcolm Dalkoff．For the last 24 years he has been a professional   26   ．Here is what he told me:
As a boy in Rock Island, Dalkoff was terribly   27   ．He had few   28   and no self-confidence．One day, his English teacher, Ruth Brach, gave the class an assignment（作业）．The students had been reading To Kill a Mockingbird．Now t

hey were to write their own chapter that would   29    the last chapter of the novel.
Dalkoff wrote his chapter and turned it   30  ．Today he can not recall anything   31
about the chapter he wrote, or what   32   Mrs．Branch gave him．What he does remember is the four words Mrs．Brach wrote in margin（空白处）of the paper：“This is   33  writing.”
Four words．They   34    his life.
“   35    I read those words, I had no idea of who I was or   36  I was going to be.”he said.“After reading her note, I went home and wrote a short story, something I had always been   37   of doing but never believed I could do.”
Over the rest of that year in school, he wrote many short stories and always brought them to school for Mrs．Brach to evaluate．She was   38    , tough and honest.“She was just what I
39  .”Dalkoff said.
His confidence   40  ．Dalkoff believes that none of this would have happened if that woman had not written those four words in the margin of his paper.

C．encouraging