Answer:
Panic attacks typically begin suddenly, without warning. They can strike at any time, when you're driving a car, at the mall, sound asleep or in the middle of a business meeting. You may have occasional panic attacks, or they may occur frequently.
Explanation:
Hope this helps
Please note I can only make out some of this, so here's the answers I can see-
Answer #5:
Left atrium, right atrium, left ventricle, right ventricle.
Answer #10:
1.2-1.5 gallons.
Answer #8:
White blood cells fight and kill off diseases.
I'll add more as I get it
EDIT!
Answer #4:
They assist in clotting your blood
Answer #14:
O, B, A, AB.
Answer:With this system, blood always flows in only one direction inside the heart. There are also valves at the bottom of the large arteries that carry blood away from the heart: the aorta and the pulmonary artery. These valves keep the blood from flowing backward into the heart once it has been pumped out.
Explanation:
I believe the answer is A
