要使有意义,则a-1010≥01010-a≥0,
解得a=1010,
故y=0,
∴am=10100=1.
故答案为:1.
My old neighbour Charles felt__________ after his children moved out.
A.lonely
B.safely
C.angrily
D.happily
常见的个人奖励计划不包括( )。
A.计件制
B.佣金制
C.收益分享计划
D.管理奖励计划