How much oxygen molecules do we breathe in each breath?

If an online school program (i.e k12, ecot) assigns me a computer, would it be ok to use social media on it? would i get in trouble? i am not really sure from reading their terms and such.

When you have proper posture, your back is arched. a. true b. false

Andra has a family history of osteoporosis. her doctor advises her to eat foods rich in calcium. which foods should she add to her diet? a. fruits, especially grapes and berries b. unsaturated fats like olive and soybean oil c. beet greens, broccoli, and cheese