Asked by i have exams tomorrow

I am answering all the questions in an exam from 2002 because these questions most likely will come up again. The question i don't know the answer to is, "In winter, people want to stop warm air getting out of their rooms. Give two examples of how this can be done." i hope this isn't a simple answer like keep the windows and doors shut or this would be a really stupid question.

search fo "winterizing"

insulation
stop drafts