Question

continents appear to be perfectly still. in fact, they are always moving. australia moves faster than most other continents. it moves north almost three inches (seven centimeters) each year. this causes problems with australias maps. as australia moves, the difference between points on the map and their actual positions on the continent grows. every few years, scientists need to improve their information with new measurements. they publish their data to share with others. this means maps of australia are always changing. the same is true of other continents. the changes just happen more slowly. the maps have to be explained delivered corrected protected

Explanation:

The text states that as Australia moves, the difference between map points and actual positions grows. Scientists improve information with new measurements. This implies maps need to be adjusted (corrected). "Explained" (giving details) isn't relevant. "Delivered" (sending) is wrong. "Protected" (keeping safe) is incorrect.

Answer:

corrected