廊道有哪些作用?如何确定各种用途廊道的形式、尺寸和位置?布置廊道系统的原则是什么?

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问题:

廊道有哪些作用?如何确定各种用途廊道的形式、尺寸和位置?布置廊道系统的原则是什么?

考点:水利工程水工建筑物水工建筑物题库
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下列各句中,划线的词语运用错误的一项是(    )(3分)

A.不少地方政府出于对政绩的渴望,加速土地财政的开发。于是他们扭曲着国家政策,剥夺了农民的生活选择权,一厢情愿地盖楼拆房,出力反而不讨好。

B.时下,俄罗斯军队正面临着严重的逃兵役现象,这样的军队怎能担起民族复兴的重担?恐怕俄罗斯20万亿卢布军费要打水漂了。

C.人生有很多起伏的念想,但在时间的纸页上,无非鸿爪雪泥。就算我们能够从时光的黑洞里找到失去的一切,你又能把这一切带在身边多久呢?

D.民工荒不是好事,但民工留乡对解决留守儿童问题却颇有好处。对于农民工个体而言,守着妻儿在家务工挣钱过日子,这样的团圆对缓解留守儿童问题是雪中送炭

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世界上最大的国际组织是联合国,其总部设在(     )

A.日内瓦

B.瑞士的洛桑

C.雅加达

D.纽约

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My grandfather lived only half a mile away from where I grew up in New York. Every day, he would walk down to our house and bring my dad newspapers. Along with the papers he would bring a small bag of treats for my two brothers and me.
Western NY had terrible winter weather: rain, sleet, or even 3 feet of snow. Even when he was 81, he still walked the half mile every single day. As a child, I looked forward to the daily treats, but now I’m older and I realize he braved the rough weather each day just to see us smile; I now value that more than anything else.
My grandfather touched many lives. A woman who had been in hospital for five years told me her story. She said my grandfather would visit her twice a week at her home: to read to her, play bridge, or just chat. It lasted for years without stop. She had few visitors. Even a hitchhiker who my grandfather had picked up for free told me of my grandfather’s influence on his life. My grandfather took the traveler to his home. After learning that the man was homeless, my grandfather gave him a place to stay. The man told me that no one had ever been so nice to him. He later found a job in a supermarket.
I was touched, but not surprised to know all of the touching stories from which I understood my grandfather’s selflessness. I have since tried to learn from him to help others. Although he died years ago, we still respect him.

After learning about his grandfather’s stories, the writer ______.

A.felt a little surprised at first
B.followed the example of his grandfather
C.was much sad all the time
D.didn’t like his grandfather’s action

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转基因作物同普通植物的区别只是多了能使它产生额外特性的基因.早在1983年,生物学家就已经知道怎样通过生物工程技术将外来基因移植到某种植物的脱氧核糖核酸中去,以便使它产生靠杂交方式根本无法获得的某种新的特性:抗除莠剂的特性、抗植物病毒的特性、抗某种害虫的特性等.用以移植的基因可来自任何生命体:细菌、病毒、昆虫等.转基因作物目前在世界上已种植有1 000万公顷左右,种植最多的是棉花、玉米和西红柿等.在实验室试种的还有莴笋、西瓜、稻谷等品种.试验的目的除了增产之外,还在于提高这种品种的抗病毒能力.但同时也有专家担心转基因作物可能对环境有危险.比如在美国种植的那种能抗虫害的玉米和棉花,可能加快出现一更难对付的害虫.这类作物的所有分子都分泌出一微量的“杀虫”一种像任何一种一样能选择杀死某害虫的“雾剂”.尤其是那些能抗除莠剂的作物,它们一旦同野生状态下的“表姐妹”杂交之后,那些“表姐妹"也就会因此而成为除莠剂无法除掉的变种了对于这种技术,尽管还有些问题需要继续研究,但这确是人类9000年作物栽培史上一场空前的革命.

根据文意,对“转基因作物”理解正确的一项是______.

A.因环境的影响脱氧核糖核酸的变化而产生额外特性的作物

B.能够产生抗除莠剂、抗植物病毒等额外基因的作物

C.一种利用移植其他生命体基因而形成的新的杂交作物

D.移植了其他生命体基因从而产生额外特性的作物

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当管线介质为高温油品(400℃以下,6.4MPA以下)时,法兰密封面应选用()。

A.橡胶石棉垫

B.耐油橡胶石棉垫

C.铁包石棉垫

D.铝垫或合金缠绕垫

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