Sentence:  Some 80 reaction tubes from 13 manifold fillings were illuminated in the temperature <WSD>range</WSD> from 40 to 85 ` in a further endeavor to determine the cause of the irreproducibility and to obtain information on the activation energy and the effect of light intensity . 
Meaning of the word marked with <WSD> tags:  an area in which something acts or operates or has power or control: "the range of a supersonic jet"