单项选择题
We've done once but failed. We'll have to do it （） time.
A．a second B．the second C．the twice D．twice
单项选择题 They are going to give a dinner（）the new director.
单项选择题 The door was（）and I could not see who she was talking to .
单项选择题 They （） going to see my mother this Sunday.
