sentence: Clocks use different ways to measure time.
sentences_after: Clocks need some sort of steady beat or motion to track the change in time. Ancient water clocks worked by the steady movement of water from a container with a hole in the bottom to another container without a hole. Other clocks use pendulums, springs and gears to track the change in time correctly.
concept_name: clock
headings: Clock Keeping time
categories: Basic English 850 words