head,shed,lead,sled,bed, 
word,curd,nerd,bird,
house,mouse,grouse,louse,blouse,
green,spleen,teen,gene,dean,bean,
fir,bur,myrrh,sir,
poop,loop,scoop,dupe,coop,soup,hoop,
knot,cot,rot,spot,dot,plot,shot,sot,lot,pot,yacht,bot,
tee,tea,sea,lee,fee,flea,knee,
top,stop,pop,mop,flop,bop,cop,glop,clop,
nip,lip,tip,rip,quip,sip,hip,dip,
jail,male,nail,scale,rail,sail,pail,kale,hail,bail,tail,tale,quail,whale,wail,gale, trail,veil,grail,
kit,pit,slit,hit,mit,nit,tit,zit,sit,wit,fit,bit,
cat,rat,hat,pat,bat,spat,mat,chat,scat,flat,slat,vat,brat,frat,
hog,dog,clog,grog,pog,log,jog,fog,

zoology