試題詳解

21. A primary focus forms after a circulating naive B cell forms a conjugate pair with ______ in the medullary cords of a lymph node, whereas a secondary focus of B-cell expansion creates the . ______. 
(A) TH1 cell； Plasma cells
(B) Cytotoxic T cell； T-cell zone
(C) Follicular dendritic cell (FDC)； Germinal center
(D) Follicular helper T cells (TFH)； Germinal center
(E) CD40 ligand； T-cell zone.