Task: Pos Tagging
Input (English): Sentence: Oliver has recently used the second-level approach with the largest snakes , and has come to these conclusions : the anaconda reaches a length of at least 37 feet , the reticulate python 33 , the African rock python 25 , the amethystine python at least 22 , the Indian python 20 {{ , }} and the boa constrictor 18-1/2 . 
Word: ,
Output (English): .