add method to find a word in a sentence.
add method to find a word in a sentence.

linas/relex,opencog/relex,anitzkin/relex,AmeBel/relex,virneo/relex,virneo/relex,rodsol/relex-temp,anitzkin/relex,ainishdave/relex,anitzkin/relex,anitzkin/relex,leungmanhin/relex,opencog/relex,AmeBel/relex,ainishdave/relex,linas/relex,rodsol/relex,opencog/relex,rodsol/relex,virneo/relex,linas/relex,rodsol/relex-temp,leungmanhin/relex,williampma/relex,rodsol/relex-temp,rodsol/relex,anitzkin/relex,rodsol/relex,AmeBel/relex,williampma/relex,williampma/relex,virneo/relex,williampma/relex,ainishdave/relex,ainishdave/relex,rodsol/relex-temp,rodsol/relex-temp,leungmanhin/relex