The easy puzzles deal with using a certain item to pass a certain obstacle, while the more difficult puzzles deal with certain combinations of using various items to pass a certain obstacle. (thatvideogameblog.com)
These standards are in place for a reason — bodies require a certain number of nutrients in certain combinations to function correctly. (fitwatch.com)
Specifically, our study examines whether certain combinations of population health activities lead to improved health outcomes when implemented over time by community organizations. (publichealtheconomics.org)