Answer: 16.7%
Explanation: Children and adolescents (ages 6 to 17 years) engage in 60 minutes or more of moderate-to-vigorous physical activity daily as described by the CDC in The Physical Activity Guidelines for Americans (second edition).
However, elementary and high schools usually run from 8 a.m to 3 pm (or 3.30pm in some cases) daily. High school students take six one-hour classes or four 90-minute classes and an hour lunch break daily.
Thus, the CDC recommends 60minutes of physical activities daily, which account to 16.7% of the total class duration (6 hours) per day.
Answer:
Marine ecosystems are characterized by factors such as availability of light, food and nutrients. Other factors that affect marine ecosystems include water temperature, depth and salinity, as well as local topography. Changes in these conditions can change the composition of species that make up the marine community.
The answer is the chemical energy of the fluids inside the wand. A glow stick is an independent, here and now light-source. It comprises of a translucent plastic tube containing detached substances that, when consolidated, make light through chemiluminescence, so it doesn't require an external vitality.
The ability of an animal to maintain a stable internal environment is called homeostasis.
WIND ENERGY drives surface ocean currents
