按被保险人的年龄分类，人身保险的种类包括（）等
A．老年保险和成人保险
B．健体保险和标体保险
C．儿童保险和成人保险
D．社会保险和商业保险
参考答案：C
Father together with his good friends was________to go out for a camp________it began to rain. [ ]
A. hardly: than
B. around: as
C. about: when
D. nearly: while
调节阀理想可调比取决于（）。
