There are three major classes of macronutrients: carbohydrates, lipids, and proteins. All three of these nutrients are needed in relatively large amounts AND they contain Calories (note the capital C which indicates kilocalories) which can be "burned" in your body to create energy for your body
Infants have high risk of catching hiv through breast milk
A. a hospital sign because its blue
It's a hard one between the last two. It would depend on the circumstances and the teen themselves. Generally speaking, teens who have parents that enforce things don't act out but on occasion some have decided to "rebel" and take an alternative route.
However, for the sake of this question, I'm going to say a teen whose girlfriend broke up with him but acts as if nothing had happened.
And transport them to the pituitary, where they're stored for later release