“保费”栏应填（）。
A．502/25/2
B．0.25%
C．0.25/1
D．此栏为空
参考答案：C
______to some parts of South America is still difficult, because parts of the continent are still covered with thick forests.
A． Orientation B． Access C． Procession D． Voyage
开启过的疫苗，有效时间是（）
A.室温24小时内
B.室温6小时内
C.室温2小时内
D.冷藏6小时内
E.冷藏2小时内
