first decade
first decision
first decreased
first degree
first degree relatives
first delivery
first demonstration
first derivative
first description
first detailed description
first detailed study
first detectable

first detection
first determination
first determined
first diagnosis
first diagnostic step
first differences
first dimension
first direct evidence
first discovery
first documentation
first documented case
first domain
first dorsal interosseous muscle

first dose
first drink
first drug
first egg
first empirical evidence
first empirical test
first encounter
first enzyme
first episode
first episode psychosis
first estimate
first evaluation
first event

first evidence
first examination
first example
first excited state
first exon
first experience
first experiment
first experimental evidence
first exposure
first extracellular loop
first factor
first failure
first family

first feeding
first feeding stage
first finding
first flowering
first follow-up
first follow-up visit
first form
first gene