He did the right thing ___ for some fresh air even in cold winter.
They _________ the habit of visiting old friends,_________ I think is great.
This is the main use that the scientists make _________ of natural resources.
Fire safety in family houses,_______ most fire deaths occur,is different to achieve.
She looks forward every spring to _________ the flower-lined garden.
There was a big argument among the children about _________ move to a new house.