相距40cm的两本书静放在一张桌子上。 Two books forty centimeters apart lie stationary on a table These data will be sent to the computing center three miles away. Before 1960. the standard of time was the interval of time between successive appearances of the sun overhead, averaged over a year, and called the mean solar day.相距40cm的两本书静放在一张桌子上。 Two books forty centimeters apart lie stationary on a table. These data will be sent to the computing center three miles away. Before 1960, the standard of time was the interval of time between successive appearances of the sun overhead, averaged over a year, and called the mean solar day