The basic principle of radioimmunoassay is A: The radiolabeled antigen reacted with excessive specific antibody B: The radiolabeled antigen reacted with a limited number of specific antibodies C: Radiolabeled antigen and unlabeled antigen reacted competitively with limited amount of specific antibody D: Radiolabeled antigen and unlabeled antigen reacted with excessive specific antibody

The function of β subunit of polymerase is A: Template binding B: Catalytic binding C: Promoter binding D: Cation binding

Cross presentation alerts ______ cells by providing ___________. A: TC; exogenous antigen on MHC I B: TC; endogenous antigen on MHC II C: TH; exogenous antigen on MHC I D: TH; endogenous antigen on MHC II

For the branches with weak growth, we should use the ( ). A: Vertical binding B: Inclined binding C: Horizontal binding D: Bow binding

An antibody is Y-shaped and has __ identical antigen-binding sites, one on each arm of the Y.

Compared with normal mice, mice immunized with antigens for many times have the larger and heavier spleens because of ( ). A: proliferation of antigen specific T cells B: proliferation of antigen specific B cells C: proliferation of antigen specific T and B cells D: proliferation of antigen non-specific T and B cells

重组抗原疫苗（recombinant antigen vaccine）

A firm offer is not binding on the seller.

A price ceiling will only be binding if it is set

Mortar is a binding material that is used in making cement-mortar.