2. Highlight the central idea in red. 3. Highlight key details in blue.
4. Write a summary of the hahaha d d c. Bxb
People started making clocks when they needed to organize their time better. They had
calendars for months and years. But they needed to track time during the day.
Early examples of clocks included sundials that measured the movement of the sun
across the sky. Then came the idea of burning objects at a certain rate, such as when
candles, oil lamps, or incense would burn past marked lines or knotted cards.
Modern clocks meet the same need with advanced technology. In the 1600s clocks were
made with a mechanical balance wheel, and progressed to a pendulum, like you see in
grandfather clocks. Today most clocks use vibrating quartz crystals, or atomic waves.
Summary: