斯金纳认为，操作行为主义的核心概念是（）
B
暂无解析
Whatisnotthemeetinglayout?
Let'sgoswimming,_______?
Thedoctor____isleavingforAfricanextmonth.
WhileIwaswaitingforher,Ikilledtime____lookingintheshowwindows.
Thetimehascome_____wemakeextensiveuseofnuclearenergy.
