Answer:
A) central
Explanation:
The lymphatic system plays a major role in specific immune responses. The lymphatic system is composed of lymph, lymphatic vessels, and lymphatic organs (bone marrow, thymus, lymph nodes, spleen, etc). These lymphatic organs help to produce and repair immune cells including lymphocytes (T cells and B cells), monocytes, and plasma cells that generate antibodies against specific pathogens. The lymphatic organs can be classified into 1-primary (central) lymphoid organs, i.e., bone marrow and thymus, that produce lymphocytes and 2-secondary lymphoid organs, i.e., spleen, lymph nodes, and tonsils, that filter out and destroy undesired pathogens. The central lymphoid organs are sites where lymphocytes can divide and proliferate.
No, only newborns should use ear tubes, because their ear holes are bigger than people from the ages between 50-65 because by the ages between 50-65 it would be too small for the tube to be able to go in.
What do you mean? like planning lessons or is that just the question?