Sentence:  Boys 32 , 23 , 31 , 17 , 30 , 19 , and 24 had `` same schedule '' at Onset and Completion ; thus early forecasting of the <WSD>pubescent</WSD> stage would appear possible for only seven boys . 
Meaning of the word marked with <WSD> tags:  (of animals especially human beings) having arrived at the onset of puberty (the age at which sex glands become functional) but not yet fully mature