-----Alice, you clean the blackboard today, _________?----- But I cleaned it yesterday.

The employee must have been dismissed by the employer last month, ____ he?

 The police were seeking more information to find out ____ the rich merchant. 

There is little doubt in your mind that he is innocent,        ?

— Peter, you feed the gold fish and the two little tortoises, ______?　— I did it in the morning; it’s a routine for me now．