60岁以上老年人用药剂量应为成年人的（）
A．相同
B．一半
C．四分之三
D．五分之三
E．以上均不是
参考答案：B
_____ of their bad habits, the boys switched from being dependent on their parents to _____ for others.
A．Having rid; sacrificing
B．To rid; sacrifice
C．Rid; sacrificing
D．Having been rid; sacrifice
