下列不是人类利用病毒为自身服务的实例的是( )
A.某些病毒可制成杀虫剂
B.用噬体治疗烧伤病人的化脓性感染
C.给高烧病人注射青霉素
D.给健康人注射流行性乙型脑炎疫苗
答案:C
In the dark street, there wasn't a single person ____ we could turn for help. [ ]
A. that
B. who
C. from whom
D. to whom
铁剂用于治疗______。
A.巨幼红细胞性贫血B.恶性贫血C.小细胞低色素性贫血D.溶血性贫血E.再生障碍性贫血