The vaccine in a flu shot contains weakened flu viruses. How does a flu shot work with the immune system?
O A. It delivers antibodies to the muscles.
B. It delivers antibiotics.
C. It activates macrophages.
D. It activates the production of memory cells.

1. describe the structure and function of the specialized cells you observed in the video. 2. research the types of cells present in the kidney.

80 points pls brainliest 1. what does a red shift mean? blue shift? 2. describe the big bang theory. according to this theory, how old is the universe? 3. scientists believe the universe is expanding. what is the evidence that supports this? 4. describe a nebula. 5. describe the 3 types of galaxies. what is a barred spiral galaxy? 6. what is a light year? how far is alpha centauri from earth? 7. describe the universal law of gravitation. be sure to include gravitational force between two objects. 8. describe the planets’ orbits around the sun. 9. what is the asteroid belt? where is it located? 10. describe rotation and revolution of earth. what determines an earth day and year? 11. how do galaxies exist? 12. compare and contrast the inner and outer planets. 13. what causes the seasons?

In what part of the body does the most muscle activity happen?