Why do we need sleep:sleeping: ? When a motor car has been running 1._____a certain length of time , it is to go into a garage for an overhaul. It is cleaned and mended and any little faults are put right so 2._____they do not become 3._____. Finally , it is filed up with petrol , the batteries are recharged , and fresh water is poured in the radiator. This is what 4._____to our bodies and minds when we go to sleep. With all activity stopped , the body has a chance to do some repair work. Poisons and waste are cleared 5.______ the bloodstream , damaged cells are replaced , tense muscles are relaxed , rested and re-fuelled 6. ______ the next day , so that we 7.______ up feeling lively and refreshed , and not tired as we 8._____when we went to bed . Even some of our dreams are part of this clearing-out process . Many of the things we have been worrying 9._____ during the day are dealt with by our brain 10._____ night . During the working-out of the problems , we receive impressions of them , often in highly disguised forms - in the shape of 11._____ Children need 12._____ more sleep than 13._____, firstly because they use up a great deal of 14 .______in their play , and also because their bodies have 15 .____provide new cells for growth as well as replace the old ones Ai giúp mik vs