Of the two brothers, Bill is ______ younger one, and he is a quiet boy, ______ that most adults like very much.

A．the; one

B．a; the one

C．a; one

D．the; the one

控制水痘传播的主要措施有哪些（）

A.隔离水痘病人至皮疹完全结痂或出疹后7天

B.易感人群积极使用抗病毒药物

C.消毒水痘病人的分泌物污染物品

D.必要时向易感人群提供被动或主动免疫预防感染

E.带状疱疹病人也应该严密隔离