问题 单项选择题

切应变γ的定义为()。

A.分布内力的集度

B.单位长度上的变形

C.使直角变小的改变量

D.直角的改变量

答案

参考答案:D

解析:

使直角变小的改变量为正值切应变。

下列两幅图反映了中国历史上的两次巨大变化的史实,仔细阅读下图并根据所学知识回答问题。

请回答:

(1)图一、图二所反映的历史性巨变分别是什么?

                                                                                                                                                            

                                                                                                                                                            

                                                                                                                                                            

(2)这两次巨变到2009年分别是多少周年了?由这两次巨变你能得出怎样的结论?

                                                                                                                                                            

                                                                                                                                                            

(3)简述这两次巨变的共同之处。

                                                                                                                                                            

                                                                                                                                                            

单项选择题 A1/A2型题