问题 单项选择题

一座露天桁架式跨街天桥,跨度48m,桥架高度3m,桥面设置在桥架下弦平面内,桥面横粱间距3m,横梁与桥架下弦杆平接,桥架上、下弦平面均设有支撑,并在桥的两端设有桥门架,如题图所示。桥架采用Q235-B钢(3号钢)制造,焊接使用E43型焊条。桥架和支撑自重、桥面自重和桥面活载由两榀桥架平均分担,并分别作用在桥架上弦和桥架下弦的节点上,如题图所示。集中荷载设计值F1=12.6kN,F2=123.6kN。桥架杆件均采用热轧H型钢,H型钢的腹板与桥架平面平行。

在已给垂直荷载作用下,桥架腹杆S2的轴心拉力设计值与()项数值相近。

A.470.4kN

B.490.4kN

C.633.0kN

D.665.2kN

答案

参考答案:D

解析:

∑y=0

阅读理解

Have you ever complained why life is so tiring? Does the sky sometimes seem dark to you? Are your studies sometimes not successful? Well, friends, cheer up and smile all the time. If you see the world with your warm heart, you will find the whole world smiles to you.

While in school, sometimes you are tired of your lessons, but have you ever noticed the happy smile on your teacher’s face when you did a good job?

One day it is fine. Just before you want to go out, it suddenly starts to rain. Maybe you would feel very sad and start complaining about the weather. But dear friends, why don’t you sit down and listen to the concert that the nature offers you? And with the timely rain, crops in the fields will grow better and better and farmers will have a good harvest.

Although everyone wants to succeed in what he tries to do, sometimes failure can’t be avoided. I think failure is not terrible, and the terrible thing is what we are afraid of it and give up hope. When we face failure, we must be confident in ourselves, draw a useful lesson from it and try our best to finish what we have decided to do. As a popular saying goes, “Failure is the mother of success.”

Attitude decided everything. With an optimistic(乐观) attitude life is easy and pleasant. Let’s smile whatever we meet and the whole world will smile to us.

小题1:People sometimes complain_______.

A.the sky is always dark

B.their studies are successful

C.they see the world with their heart

D.life is tiring小题2:If there is a timely rain, ______.

A.you want to go out

B.you can listen to the concert

C.crops in the fields will grow better

D.farmers can’t have a good harvest小题3:When we face failure, we _________.

A.must be confident in ourselves

B.shouldn’t be afraid of it

C.shouldn’t give up hope

D.All of the above

单项选择题