“The Olympic flame will burn forever,” said Liu Qi, ____ president of the Beijing organizing Committee of ___ 29th Olympic Games.

A．不填; the

B．the; the

C．the; 不填

D．a; the

如果进栈序列为e1，e2，e3，e4，则可能的出栈序列是

A．e3，e1，e4，e2

B．e2，e4，e3，e1

C．e3，e4，e1，e2

D．任意顺序