The secondary lymphoid tissues include the__________
and_____________
a. Thymus; Bone Marrow
b. Bone Marrow; Tonsils
c. Spleen; Thymus
d. Spleen; Lymph Nodes
and_____________
a. Thymus; Bone Marrow
b. Bone Marrow; Tonsils
c. Spleen; Thymus
d. Spleen; Lymph Nodes