Combine the following sentences into one complex sentence :
(a) The sun sets in the west. It is a fact.
(b) The teacher is saying something. Pay attention to it.
(c) He will go to Krishna Memorial Hall. I do not know the time.
(a) That the sun sets in the west, is a fact.
(b) Pay attention to what the teacher is saying
(c) I donot know the time when he will go to Krishna Memorial Hall.
