一人以每分钟60米的速度沿铁路步行,一列长144米的客车对面开来,从他身边通过用了8秒钟,列车的速度是____ 米/秒.
—Are Jim and Bob playing outside?
—_______. They are doing their homework in the study.
古罗马的第一部成文法是( )