The number of players in this year's sports meet was half ______.   [    ]

A. last year's      

B. that of last year's

C. of last year's    

D. those of last year's

如图是“俄罗斯方块”游戏的一个画面，若使左上角的图形平移后插入到下面的空白处，应先向（    ）平移（    ）个单位，再向（    ）平移（    ）个单位。