c a m e l _
do not double (camel)
M a r s _
do not double (Mars)
s h e l _
double! (shell)
t h i e f _
do not double (thief)
c h e s _
double! (chess)
c u f _
double! (cuff)
g r i l _
double! (grill)
h u f _
double! (huff)
s u r f _
do not double (surf)
s t i f _
double! (stiff)
e n g u l f _
do not double (engulf)
h o o f _
do not double (hoof)
s e a l _
do not double (seal)
f r i z _
double! (frizz)
s h e l f _
do not double (shelf)