One ought ________ for what one hasn't done.

--- We want someone to design the new art museum for us.--- ____ the young fellow outside have a try?

—The party was a great success. Why didn’t you come?   —I wish I_______. 

--- My son is _____ to be seen. Where has he gone? --- I think he _____ in the building. 

My sister met him at the Grand Theater yesterday afternoon, so he ________ your lecture.