The largest source of oxygen released into the atmosphere is from the:
a. ozone
b. fossil fuel
c. sahara desert
d. rainforest

According to the article, when our sleep/wake cycle breaks down, we are at an increased risk for all but which select one: a. respiratory illnesses b. dementia c. diabetes d. heart disease

Why is a lunch consisting of pizza, fruit, and salad a better choice than a lunch with the same number of calories from pizza alone? a)both lunches provide the same amount of energy but the lunch of pizza, salad, and fruit provides more nutrients. b)both lunches provide the same amount of nutrients but the lunch of pizza, salad, and fruit provides more energy. c)both lunches are healthful but the lunch of pizza, salad, and fruit provides more energy for metabolism. d)both lunches are healthful but the lunch of pizza, salad, and fruit is likely to have a higher fat content.

What angle should your knees not bend past when squatting? a. 30 degrees b. 45 degrees c. 90 degrees d. 120 degrees