问题 单项选择题

钢筋混凝土梁在正常使用荷载下,下列哪一项叙述是正确的

A.通常是带裂缝工作的
B.一旦出现裂缝,裂缝贯通全截面
C.一旦出现裂缝,沿全长混凝土与钢筋间的粘结力消失殆尽
D.不会出现裂缝

答案

参考答案:A

解析: 混凝土抗压强度较高,而其抗拉强度很低。在正常使用荷载作用下,钢筋混凝土梁截面受拉区混凝土很快会达到其抗拉强度而开裂,由于钢筋承担拉力,梁并没有丧失承载力。因此,一般情况下,允许梁出现裂缝,但是要限制裂缝的宽度。

单项选择题
阅读理解

阅读理解

     As kids, my friends and I spent a lot of time out in the woods.  " The  woods "  was  our  part-time  

address,destination, purpose, and excuse. If I went to a friend's house and found him not at home, his

mother might say,"Oh.he's out in the woods."  with a tone (语气)  of airy acceptance. It's similar to the

tone people sometimes use nowadays to tell me that someone I'm looking for is on the golf course or at the gym,or even "away from his desk".For us ten-year-olds, " being out in the woods"  was just an excuse to

do whatever we feel like for a while.

     We sometimes told ourselves that what we were doing in the woods was exploring (探索). Exploring was a more popular idea back then than it is today. History seemed to be mostly about explorers. Our

explorations, though, seemed to have less system than the historic kind: something usually came up along

the way. Say we stayed in the woods ,throwing rocks, shooting  frogs , picking  blackberries , digging 

 in  what we were briefly persuaded was an Indian burial mound.

     Often we got "Lost" and had to climb a tree to find out where we were. If you read a story in which

someone does that successfully, be skeptical; the topmost branches are usually too skinny to hold weight,

and we could never climb high enough to see anything except other trees. There were four or five trees that we visited regularly-tall beeches, easy to climb and comfortable to sit in.

     It was in a tree, too, that our days of fooling around in the woods came to an end. By then some of us

has reached seventh grade and had begun the rough ride of adolescence (青春期). In March.the month

when we usually took to the woods again after winter, two friends and I set out to go exploring. We

climbed a tree,and all of a sudden it occurred to all three of us at the same time that we really were rather

big to be up in a tree. Soon there would be the spring dances on Friday evenings in the high school

cafeteria.

1. The author and his friends were often out in the woods to__________.  

A. spend their free time

B. play golf and other sports

C. avoid doing their schoolwork

D. keep away from their parents

2. What can we infer from Paragraph 2?   

A. The activities in the woods were well planned.

B. Human history is not the result of exploration.

C. Exploration should be a systematic activity.

D. The author explored in the woods aimlessly

3. The underlined word "skeptical"  in Paragraph 3 is closest in meaning to _________.    

A. calm    

B. doubtful    

C.serious    

D. optimistic

4. How does the author feel about his childhood?   

A. Happy but short.

B. Lonely but memorable.

C. Boring and meaningless.

D. Long and unforgettable.