Sixteen-year-old manuel is going to bed later and later, perhaps because of increased neural sensitivity to evening light. manuel's parents should know that he needs about hours of sleep per night.

9

Explanation:

Sleep requirements vary from person to person and also on the factor of age. Children and teens need more hours of sleep in order to remain healthy and functionable. Teens needs about 9 hours of perfect sleep each night in order to function the best that they can be.

However, biological patterns of sleep suggest that during adolescence, the teens shift their timing for sleep towards later times and thus, sufficient amount of sleep is required.

From the given question, Manuel's parents must know that he needs approximately 9 hours of sleep per night.

answer: hey improve the marine life in a certain area.

they provide a new location for fishermen to fish and which works to ease the pressure on natural reefs.

they are a great way to get rid of large objects that would otherwise be placed on landfills

explanation:

answer: b has a great day

explanation: