Only when your identity has been checked, ___________.

— Should people stop using their cars and start using public transport?— __________. The roads are too crowded as it is.

A significant proportion of such children are condemned______.

— Have you been to the Great Wall? —Perhaps not in my memory. ________, it might have been during my early childhood.

No sooner had I come to the office _____ the boss told me that I was fired.