Sentence:  The Book of Change" in the general form it is known today <nowiki>[</nowiki>sic<nowiki>]</nowiki> is approximately three thousand years old. It is the third in a series of such texts, its <WSD>antecessors</WSD> supposed by some scholars to have been composed six and twelve hundred years earlier. 
Meaning of the word marked with <WSD> tags:  A person or thing that precedes or goes before.<ref>(Ephraim Chambers), "(Cyclopædia, or an Universal Dictionary of Arts and Sciences)," London: James and John Knapton, 1728, Volume(nbsp)1, p.(nbsp)106: “<small>ANTECESSOR</small>, one that goes before, or leads another. (...) The Term is particularly used in some Universities for a Professor, who teaches, or lectures the Civil Law.”[https://babel.hathitrust.org/cgi/pt?id=gri.ark:/13960/t85j10m9v&view=1up&seq=146]</ref>