Geographic education involves more than teaching in school. it could be: a. making movies for research classes b. printing magazines for science students c. making presentation materials for a conference d. all of the above

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes.b. it burns more cleanly than crude oil products.c. scientists have developed new ways of extracting it.d. during its extraction, groundwater can be contaminated.