Instead we must mark our journey with mileposts of our own invention, seconds minutes, hours, days, weeks, months, and years.

相反，我们必须用自己发明的里程碑、秒、分钟、小时、天、周、月和年来标记我们的旅程。

Where the City ends there is a great road winding off to the north, and we Street Sweepers must keep this road clean to the first milepost.

在城市的尽头， 有一条大路蜿蜒向北， 我们清道夫必须保持这条路清洁到第一个里程碑。