Sentence:  If tyrosine and a system generating <WSD>hydrogen</WSD> peroxide are added to a cell-free homogenate of the thyroid , large quantities of free mono-iodotyrosine can be formed ( Alexander , 1959 ) . 
Meaning of the word marked with <WSD> tags:  a viscous liquid with strong oxidizing properties; a powerful bleaching agent; also used (in aqueous solutions) as a mild disinfectant and (in strong concentrations) as an oxidant in rocket fuels