one author
one base
one based
one being
one branch
one breeding season
one case
one case only
one category

one cause
one cell
one cell line
one cell type
one center
one centre
one child
one chromosome
one clade
one class

one cohort
one combination
one community
one component
one compound
one concentration
one condition
one consisting
one context
one control

one copy
one corresponding
one country
one county
one course
one criterion
one culture
one cycle
one day
one death

one decade
one degree
one derivatives
one described