variety of plants
variety of populations
variety of problems
variety of processes
variety of proteins
variety of purposes

variety of reactions
variety of reasons
variety of responses
variety of scenarios
variety of settings
variety of situations
variety of solid tumors

variety of solvents
variety of sources
variety of species
variety of stakeholders
variety of stimuli
variety of strategies
variety of stresses

variety of structures
variety of studies
variety of substrates
variety of symptoms
variety of systems
variety of taxa
variety of techniques

variety of tissues
variety of tools