春秋战国时期“百家争鸣”局面出现的根本条件是 [ ]
A、社会经济发展
B、“士”阶层壮大
C、各国招揽人才
D、阶级关系的变化
答案：A
When the adjacency matrix method is used to store a graph, which of the statements is (are) true ( ) Ⅰ．the space required depends on the number of vertices Ⅱ．the apace required depends on the number of edges
A．None
B．Ⅰ only
C．Ⅱ only
D．Ⅰ and Ⅱ
对某市七个区的ＳＯ2年平均浓度作比较，应绘制（）图：
A.构成图
B.直条图
C.直方图
D.线图
E.曲线图
