Answer:
option 3 in 1st one and option 4 in 2nd one I think
The moon revolves around the Earth as a natural satellite.
Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
Answer: The structure and curvature of the Earth results in beams of sunlight glancing off the equator and reaching other areas of the Earth. This means that the areas at the equator receive more energy as the sun's rays hit them directly. :)
