Paragraph Two
Do we really need 8 hours' sleep? While most scientists agree that between seven and nine hours a night is optimal, this is just a rough estimate. It seems that how many hours of sleep you need depends upon your age——with infants n

Paragraph Two
Do we really need 8 hours' sleep? While most scientists agree that between seven and nine hours a night is optimal, this is just a rough estimate. It seems that how many hours of sleep you need depends upon your age——with infants needing much more than adults. What does seem apparent is that around seven and a half hours' sleep is a good choice.

The proper a() of sleep people need.

amount