One of the challenges that faced ancient civilizations like Egypt was timekeeping, calendars.
2
早在数千年前,古代中国、希腊和其它很多古代文明就发明了各种各样的精确计时仪器。
Various types of instruments to accurately measure the passage of time were invented in ancient China, Greece, and other civilizations thousands of years ago.
3
水钟,亦称漏壶,利用水的流动计时的古代时钟。
Water clock: or clepsydra, Ancient device for measuring time by the gradual flow of water.