东北落叶松(TCl7-B)原木檩条(未经切削),标准直径为162mm,计算简图如图所

题型:单项选择题

问题:

东北落叶松(TCl7-B)原木檩条(未经切削),标准直径为162mm,计算简图如图所示,该檩条处于正常使用条件,安全等级为二级,设计使用年限50年。

若不考虑檩条自重,试问,该檩条达到挠度限值l/250时,所能承担的最大均布荷载标准值qk(kN/m),与下列何项数值最为接近()

A.1.6

B.1.9

C.2.5

D.2.9

考点:二级注册结构工程师二级结构师专业知识一、二级注册结构工程师专业部分
题型:单项选择题

下面右图是左图沿河流方向所绘制的素描图,读图回答下列各题。

小题1:右图是左图中哪个地点的耕地,向哪个方向所画的素描。

A.甲西南

B.乙东南

C.丙东北

D.丁西北小题2:图中耕地最可能的农作物为

A.咖啡

B.天然橡胶

C.菠萝

D.蔬菜

题型:单项选择题

(三)

Believe it or not, optical illusion can cut highway crashes.

Japan is a case in point. It has reduced automobile crashes on some roads by nearly 75 percent using a simple optical illusion. But stripes, called chevrons, painted on the roads make drivers think that they are driving faster than: they really are, and thus drivers slow down.

Now the American Automobile Association Foundation for Traffic Safety in Washington D. C. is planning to repeat Japan’s success. Starting next year, the foundation will paint chevrons and other patterns of stripes on selected roads around the country to test how well the patterns reduce highway crashes.

Excessive(too great) speed plays a major role in as much as one fifth of all fatal traffic accidents, according to the foundation. To help reduce those accidents, the foundation will conduct its tests in areas where speed-related hazards(danger) are the greatest curves, exit slopes, traffic circles, and bridges.

Some studies suggest that straight, horizontal bars painted across roads can initially cut the average speed of drivers in half. However, traffic often returns to full speed within months as drivers become used to seeing the painted bars.

Chevrons, scientists say, not only give drivers the impression that they are driving faster than they really are but also make a lane appear to be narrower. The result is a longer lasting reduction in highway speed and the number of traffic accidents.

On roads painted with chevrons, drivers tend to feel that().

A.they should avoid speed-related hazards

B.they are driving in the wrong lane

C.they should slow down their speed

D.they are coming near to the speed limit

题型:单项选择题

某课外兴趣小组,将塑料桶中分别装满密度已知的四种不同液体后,用弹簧测力计称出它们的重力,记录的数据如下表所示:

(1)求空塑料桶的重力

(2)塑料桶的容积是多少dm3

(3)若小桶中盛满密度是1.8g/cm3的液体,则测力计的示数是多少?

(4)若弹簧测力计的量程是5N,则所能测量的液体的密度最大是多少?

题型:单项选择题

某男,经常以拖延、蓄意无效率等形式的被动阻抗来应付应完成的任务,凡事挑剔归罪于他人,并讨厌别人对他提任何要求。其最可能的诊断为()。

A.反社会型人格

B.偏执型人格

C.边缘型人格

D.回避型人格

E.被动-攻击性人格

题型:单项选择题

近年来,城市人口爆炸,富含有机物的生活污水横溢,污染环境。为加强水体治理,长江流域某城市构建了较大面积的人工湿地(如下图)。请回答:

有机污染物不断地随生活污水流入该湿地,一段时间后,湿地中出现了轮虫等浮游动物,它们可控制绿藻等浮游植物的数量;管理员还放养了一些鱼和鸭,为城市增添了自然气息。请写出一条可能存在的食物链()

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