rabbit - railing
railroad - rampant
rampart - rational
rationalize - read
reader - rebel
rebellion - reciprocate
recite - recount
recover - redundant
reed - refrigerator
refuel - regularly
regulate - relatives
relatives - remedy
remember - reorganize
repair - reportedly
reporter - required
requirement - resident
residential - respect
respect - restraints
restrict - retract
retreat - reverse
reverse - rhyme
rhythm - rickshaw
riddle - rigid
rigorous - rite
rival - robbery
robe - roomy
Roosevelt - round-trip
roundworm - ruin
ruined - running
running - Ryukyu