ei2 ei2 ei2 ei2
ei2 ei2 ei2 ei2
co co co co
ei2 ei2 ei2 ei2 .
e˨ j˥ WORD_BOUNDARY e˨ j˥ WORD_BOUNDARY e˨ j˥ WORD_BOUNDARY e˨ j˥ WORD_BOUNDARY
e i 2 WORD_BOUNDARY e i 2 WORD_BOUNDARY e i 2 WORD_BOUNDARY e i 2 WORD_BOUNDARY . WORD_BOUNDARY