試題詳解

28. Which is the correct order of steps taken by B and T cells to defend against infection in body fluids and cells?
1. B and T cells move to the lymph nodes, spleen, and other parts of the lymphatic system.
2. B and T cells leave the bone marrow and thymus and move to the bloodstream.
3. B and T cells meet and begin to fight viruses or other infectious agents.
4. B and T cells develop antigen receptors.
(A) 4, 2, 3, 1
(B) 2, 4, 3, 1
(C) 4, 3, 2, 1
(D) 2, 4, 1, 3
(E) 4, 2, 1, 3