Ask questions about the sentence: the head teacher proposed that we come to his school for 15-20 days in april. how ?

The Head Teacher proposed that we come to his school for 15-20 days in April.
Did the Head Teacher propose that we come to his school for 15-20 days in April?
Who proposed that we come to that  school for 15-20 days in April?
Where will we come for 15-20 days in April?
When will we come to the school, that the Head teacher proposed?
How long will we stay in the school for?

Did the head teacher propose that we come to his school for 15-20 days in april?
who propose that we came to his school for 15-20 days?
Where did the head teacher propose that we came for 15-20 days in april?
When did the head teacher propose that we come to his school for 15-20days?
How long did the head teacher propose that we come to his school in april?