one percent
one period
one person
one phase
one piece
one place
one plane
one plot
one point

one polymorphism
one population
one position
one possible exception
one pot
one practice
one pregnancy
one prescription
one procedure
one process

one product
one protein
one quarter
one question
one race
one reaction
one reason
one recurrence
one region
one report

one representative
one residue
one response
one reviewer
one risk factor
one sample
one scale
one school
one season
one second

one section
one sector
one seizure
one semester