A:B细胞接受刺激后形成效应B细胞能使靶细胞裂解
B:疫苗能够将流感病毒杀死
C:免疫系统受损的病人在接种疫苗后仍可能患流感
D:疫苗在进入人体后只会引起机体的体液免疫
下列有关仪器刻度位置的叙述正确的是
______swimming here. It's dangerous.
Having retired from business, he now ____(忙于) himself with the welfare of the disabled.