搜题请搜索小程序“爱下问搜题”
问题 单项选择题

两个截面尺寸、混凝土强度等级相同的轴心受拉构件配有不同面积和不同级别的钢筋，混凝土开裂后，钢筋应力增量△σs的变化是( )。

A．强度高的钢筋△σs大
B．两种钢筋△σs相等
C．As大的钢筋△σs大
D．As小的钢筋△σs大

答案

参考答案：D

解析：混凝土即将开裂时[*]
混凝土开裂瞬间：[*]，故[*]
钢筋面积As与△σs成反比，故选D

补全对话，情景问答
读问句，选答语。

( ) 1. Good work!
( ) 2. Can I help you?
( ) 3. Where is the TV?
( ) 4. What's for lunch?
( ) 5. What's Mum doing?

A. She's cooking beef. 
B. It's in the living room.
C. Thank you. 
D. Sure.
E. Some cabbages and meat. 
查看答案
补全对话，情景问答
从方框中选出合适的句子，补全对话。
A: What are you doing, Lucy?
B: 1              
A: Oh. How about me wearing a shirt and tie?
B: Where are you going?
A: To Mary's birthday party. 2              
B: If I were you, I would not wear a shirt and tie. 3              
A: Maybe you are right.
B: 4              
A: Oh, no.
B: Really? 5              
A: OK! Let's go to buy a present. Be quick!

A. Have you had a present for the party?
B. I'm reading a newspaper.
C. Don't you think it's too formal (正式的)?
D. What if everyone else brings a present?
E. I really don't know what to wear.
查看答案