one device
one diagnosis
one diastereomer
one dimension
one dimer
one direction
one disease
one disorder
one dog

one domain
one donor
one dose
one drug
one edge
one egg
one electron
one element
one enantiomer
one end

one entity
one enzyme
one episode
one equivalent
one ethnic group
one event
one examiner
one example
one exception
one expected

one experiment
one extreme
one eye
one face
one facet
one factor
one failure
one family
one female
one fetus

one field
one fifth
one firm
one foot