問題詳情

7. The second vaccination is beneficial because it
(A) contains mast cells that survive longer than 4-5 days.
(B) stimulates production of a higher concentration of antibodies in the bloodstream.
(C) requires two injections to stimulate antibody formation.
(D) keeps previously produced cytotoxic T cells circulating in the bloodstream.

參考答案

答案：[無官方正解]
難度：計算中-1
書單：沒有書單，新增