传染病潜伏期的意义有()
A.判断预后
B.确定检疫期
C.协助治疗
D.协助诊断
E.确定病程长短
参考答案:B, D
25.We don’t have enough greeting cards for here ,but our best wishes are for all of you !
A.anyone
B.someone
C.everyone
D.no one
简述桑代克的学习联结观。