Tuesday 9 October 2012

DAY AND NIGHT ON EARTH



Humans use day and night as signals for our daily activities. When the sun comes up in the morning, we get out of bed and go to school, work or play. When night arrives, we end our activities and go to sleep.We use the cycle of the day as a way to identify when we should be active and when we should rest. But what causes the change from day to night? Here is the explanation.






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