Once __________sport has become less popular, it has to make __________way for new sport which are more popular to enter into the Olympics.

A．the；a

B．a；／

C．／；the

D．the；／

（）理论认为，引起人们工作满足的因素与工作不满的因素是截然不同的两类因素，分别称之为激励因素和保健因素。

A.双因素理论

B.需要层次理论

C.期望理论

D.强化理论