A:the 1980s; his twentie
B:the 1980s; the twentie
C:the 1980s; twentie
D:1980s; the twentie
某班体育委员对七位同学定点投篮进行数据统计,每人投十个,投进篮筐的个数依次为:5,6,5,3,6,8,9.则这组数据的平均数和中位数分别是( )
依据板块构造理论,下列属于火山地震多发区的是( )
读图,回答下列问题。