Sentence:  Onsets , Completions , and Skeletal Ages ( Hand ) of boy 34 and girl 2 may be directly compared and classified , <WSD>using</WSD> only those Skeletal Ages which appear immediately below the Onset Profile and the Completion Profile . 
Meaning of the word marked with <WSD> tags:  put into service; make work or employ for a particular purpose or for its inherent or natural purpose