DNA is something everyone has in them to see
The right answer is HEPA filter.
A HEPA filter (High Efficiency on Particles Air) can filter up to 99.97% of 0.3μ aerial particles.
These filters are used to clean the air and retain suspended particles (dust, pollen, bacteria etc.) and other particles that can cause respiratory allergy in sensitive subjects.
They are very used in sterile rooms
Veins don’t always conduct oxygen poor blood. The pulmonary vein brings reoxygenated blood from the lungs into the heart
Answer:
The answer is freedom.
Explanation:
All the others do not evoke positive feelings, but freedom does. it also says 'the answer is freedom' at the end of your post!
Avoid carcinogens (like smoking residues..etc), eat healthy and sleep well in order to maintain a strong immune system
