Is radiation from the sun always harmful?

Enzo sits with a small group of friends at lunch. lately, he has been very quiet and stays home a lot even though his friends invite him to go places. he likes to play video games in his free time and is slightly overweight. which behavior is a sign that enzo may need professional mental health treatment? a) being overweight b) playing video games c) withdrawing from activities d) having a small group of friends

Explain what you know about the cause of mental illnesses.

Why do you need two different circuits of blood vessels in your body?