different substrate specificities
different substrate temperatures
different substrates
different subtypes
different subunits
different successional stages
different sugars
different supports
different surface areas
different surface chemistries
different surfaces
different surgical techniques
different susceptibilities
different symmetries
different symptoms

different system parameters
different systems
different tactics
different targets
different tasks
different taxa
different taxonomic groups
different taxonomic levels
different techniques
different techniques used
different technologies
different temperature regimes
different temperatures
different temporal
different terms
different testing methods

different tests
different textures
different theoretical perspectives
different theories
different therapeutic approaches
different therapeutic strategies
different therapies
different thickness
different things
different thresholds
different time-points
different time-scales
different time courses
different time intervals
different time periods
different time points

different time scales
different time steps
different times
different tissue types
different tissues
different tools
different topics
different topologies
different traditions
different traits
different trajectories
different traps
different treatment approaches
different treatment groups
different treatment methods
different treatment modalities

different treatment options
different treatment regimens
different treatment strategies
different treatments
different tree species
different trends
different trophic levels
different trophic status
different tumor types
different tumors
different turbulence models