下列计算正确的是( )
A:a3+a2=a5
B:a3﹣a2=a
C:(a3)2=a5
D:a3•a2=a5
一名射击爱好者7次射击的中靶环数如下(单位:环):7,10,9,8,7,9,9,这7个数据的中位数是( )
Henry refused our invitation, because he was really busy.