A:甲的速度小于乙的速度
B:经过3s,甲、乙相距9m
C:乙到达P 点时,甲离Q 点6m
D:甲到达Q 点时,乙离P 点4m
词语运用
①The old man is d____.He can't hear anything.
②My dog is m____.Can you help me find it?
③All of them are ____(注视) at the computer screen.
④We don't know whether he's ____(活着)or dead.
⑤The road was so narrow(狭窄)that cars were unable to ____(通过).
“政府铸造的铜钱超过前朝十倍以上,但仍不敷应用。在缺铜的情形下,民间开始发行纸币。”这一现象最早应出现在( )