不通车仅供游人行走的花岗岩园路基层做的现浇C25混凝土垫层可厚()。A、100 B、1

题型:单项选择题

问题:

不通车仅供游人行走的花岗岩园路基层做的现浇C25混凝土垫层可厚()。

A、100

B、120

C、150

D、250

考点:园林基础知识园林绿化工程概论园林绿化工程概论题库
题型:单项选择题

阅读下面材料:

夜幕降临了,夜蛾飞了出来,它身体比蝴蝶粗壮,喜欢绕火光飞舞.因为夜蛾的幼虫是农业害虫.消灭它!蝙蝠从天而降,用“超声雷达”搜索着,突然发现了夜蛾(图).那夜蛾也发现了蝙蝠,它好象已经知道自己危在旦夕,马上变换了飞行方向,兜圈子,翻筋斗,螺旋下降,最后收起翅膀,径直落到了花草之间.具有精细超声的蝙蝠扑空了.

夜蛾是怎么逃避蝙蝠追击的呢?它怎么会感觉出蝙蝠来临的呢?

一些科学家研究了这场有趣的搏斗.多伦多大学的生物学家J.H..富勒特发现,蝙蝠在捕食时,要同时发出不同频率的超声波去搜索猎物.蝙蝠一但探索到猎物,它的发声频率便会骤然升高.

蛾的胸部有一个像气泡一样的隆起物,当蝙蝠的超声信号传来时,那隆起物在飞行肌的压力下,会起伏不平,发出与蝙蝠定位回声极相似的超声波,就如同蝙蝠要碰墙壁一样.要是蝙蝠有时间仔细去“想”一下,也许它会判断出那是假信号,不是自己的回声,但是,蝙蝠飞行速度大约是5m/s,它只有千分之一秒的时间来决定自己下一步的飞行方向.为了避免碰壁,它只好转向而飞,受了夜蛾的欺骗;有些蛾还有自己的“超声雷达”,它们主动发射极高频的超声波,一旦发现蝙蝠便逃之夭夭;有的夜蛾身上长着一种奇特的绒毛,它能吸收超声波,使蝙蝠得不到一定的回声,自己好蒙混过关.

看来,能吸收雷达的现代最新式的隐形飞机,不过是夜蛾的祖传技术的仿效而已.

请回答:通过阅读,你有什么收获和感受?

题型:单项选择题

结合语境,将下列句子依次填入横线处,顺序最恰当的一项是

深夜听泉,别有一番滋味。泉声浸着月光,听来格外清晰。白日里浑然一片的泉鸣,此时却能分出许多层次:那     者,是草丛中淌过的小溪;那     者,是石缝间漏下的滴泉;那     者,应为万道细流汇于空谷;那     者,定是激流直下陡壁,飞瀑落入深潭。至于泉水绕过树根,清流拍打着卵石,则轻重缓急,远近高低,各自发出互不相同的音响。这万般泉声,被一支看不见的指挥棒编织到一起,汇成了一首奇妙的交响曲。

①清脆如弹拨   ②厚重如贝司轰响   ③柔曼如提琴   ④雄浑如铜管齐鸣

A.①②③④

B.①③②④

C.③①②④

D.④②③①

题型:单项选择题

驾驶人在驾驶证有效期满前多长时间申请换证?

A.30日内

B.60日内

C.90日内

D.6个月内

题型:单项选择题

(Ⅱ)

One day while a girl was walking in the woods she found two starving songbirds. She took them home and put them in a small (31) . She cared for them and felt great love for them.

Once the (32) and per of the two birds flew from the cage. Therefore, (33) he flew close, she grasped him (34) . She felt glad, but suddenly she felt the bird go limp. She opened her hand and (35) in horror at the dead bird.

She noticed the other bird moving back and forth on the edge of the cage. She could feel his great need for (36) . She lifted him from the cage and (37) him softly into the air. The bird circled once, twice, three times.

The girl watched delightedly at the bird’ s enjoyment. Her heart was no longer (38) with her loss. Suddenly the bird flew closer and (39) softly on her shoulder. It sang the sweetest melody that she had ever heard.

The fastest way to (40) love is to hold on it too tightly, while the best way to keep love is to give it WINGS!

35()

A. stared

B. glared

C. glanced

D. shouted

题型:单项选择题

计算机的发展经历了电子管计算机、晶体管计算机、()、大规模超大规模集成电路计算机等四个阶段。

A.纳米计算机

B.生物计算机

C.集成电路计算机

D.网络虚拟计算机

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