TREAT
TREATED
STUDY
STUDIED
CONTAMINATE
CONTAMINATED
ESTABLISH
ESTABLISHED
BE
WAS / WERE
SHOW
SHOWED
WEAR
WORE
RETURN
RETURNED
ARRIVE
ARRIVE
IMPROVE
IMPROVED
WRITE
WROTE
INFEST
INFESTED
MARRY
MARRIED
TRAVEL
TRAVELLED
LIE
LAY
ASSEMBLE
ASSEMBLED
REDUCE
REDUCED
MOVE
MOVED
USE
USED
PERFORM
PERFORMED
MAKE
MADE
HELP
HELPED
ASK
ASKED
SAIL
SAILED
BE BORN
WAS BORN
ENROL
ENROLLED
INVENT
INVENTED
RECEIVE
RECEIVED