Sentence:  The rate of oxygen transfer at 1.0 - mg / l dissolved <WSD>oxygen</WSD> concentration and 10 ` C for various rotor speeds is given in Table 3 , . 
Meaning of the word marked with <WSD> tags:  a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust