OBSTRICTION

bi bo in is it no oi on or os si so ti to

bin bio bis bit boo bos bot bro cis cob con coo cor cos cot ins ion its nib nit nob noo nor nos not obi ono ons oot orb orc ors ort rib rin rob roc rot sib sic sin sir sit sob son sot sri tic tin tis tit ton too tor tot

bins bint bios biro bits bitt boon boor boos boot born bort bots bott brin brio bris brit broo bros cion cist cobs coin coir coni cons coon coos coot corn cors cost cots crib cris crit ibis icon inro inti into ions iris iron nibs nisi nits nobs noir nori obis obit onos onto oots orbs orcs orts otic otto ribs rins riot robs rocs root roti roto rots scot snib snit snob snot soon soot sorb sori sorn sort stir stob stot tics tins tint tiro titi tits toit tons toon toot torc tori torn toro tors tort tost tots trio trot