A:波速为0.5 m/s
B:波的传播方向向右
C:0~2 s时间内,P运动的路程为8 cm
D:当t=7 s时,P恰好回到平衡位置
Police: What's in your wallet?
Owner: There ______ some money and two tickets for today's e-sports competition.
春秋争霸战争的客观进步性表现在( )