在时间平均的基础上间断地实施奖励是下列哪种强化方法:()
A.固定间断
B.固定比率
C.变动间断
D.变动比率
参考答案:C
I wish I could go to Mars one day.
A.a few days.
B.that day.
C.in one day.
D.some day.
旅游团离开的前一天,地陪应及时将证件归还游客,并当面向客人点清数目。()
A.正确
B.错误