Answer:
The answer is c
Explanation:
the the immune system protects the body against harmful pathogens by producing special proteins called antibodies.
Answer:
pericardium
Explanation:
A double-walled membrane, the pericardium, separates the right and left chambers, preventing oxygen-rich blood from mixing up with the one without oxygen. So, the heart functions go smoothly. Deoxygenated blood enters the right atrium.
Answer:
D
Explanation:
These colors are also referred to as primary colors. When mixed in different proportions, they can produce a variety of secondary and tertiary colors and this is how the human eye is also to perceive many colors even with only these three eye pigments.