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

------______do you go to the city park?------Usually by bike.

I suppose he ought to have known that,________?

—What’s wrong with my computer, Jack?—Let me have a check. OK, it works now.—You mean, nothing wrong with it, ________ ?

 --         did you visit the Science Museum? --Three months ago.