Every person is unique   and so are our sleep needs. But in today's busy world, how much sleep should we be getting each night? Research suggests that most healthy adults need seven to nine hours of sleep each night. Children and teens need even more sleep than adults. The following is a breakdown of the recommended   number of hours of sleep people need by age: INFANTS (0 to 2 months): .........................15 to 18 hours (2-12 months): ...........................14 to 15 hours CHILDREN (12-18 months): ........................13 to 15 hours (18 months-3 years): .................12 to 14 hours (3-5 years): ................................11 to 13 hours (5-12 years): ...............................9 to 11 hours TEENS (13-19 years): .............................8.5 to 9.5hours ADULTS (more than 20 years): .................7 to 9 hours As children grow, they go through many changes, including changes in sleep. Children and teens, like adults, need a regular sleep and wake timetable, even on weekends. Sleep should follow a relaxing bedtime plan. The bedroom should be cool, dark and quiet. Getting a good night's rest may become more difficult as they grow older because of more responsibilities   and activities, the influence of TV, computers and so on. However, sleep is still an important part of teens' health and overall quality of life. So, how do teens measure how much sleep they need? If a teen has trouble staying awake during school, they probably are not getting enough quality sleep.  Most sleep problems are treatable. If teens are having trouble in getting enough sleeps they need, it is important to see a doctor or other health experts. For good sleep, the bedroom should be   _  .
clean and tidy wet and noisy cool, dark and quiet warm and quiet