The advent of the Bronze Age (about 3200 b.c. ), and the spread of city-states ruled by kings, is marked by the appearance of royal tombs containing bronze objects in such places as Troy in the west, and Alacah??y??k near Ankara.
( ( ( ( ( ( ( ( ( ( ( The advent ) ( of ( ( the ( Bronze Age ) ) ( -LRB- ( ( about ( 3200 b.c. ) ) -RRB- ) ) ) ) ) , ) and ) ( ( the spread ) ( of ( city-states ( ruled ( by kings ) ) ) ) ) ) , ) ( is ( ( marked ( by ( ( the appearance ) ( of ( royal tombs ) ) ) ) ) ( ( ( containing ( bronze objects ) ) ( in ( such places ) ) ) ( as ( Troy ( in ( the west ) ) ) ) ) ) ) ) , ) and ) ( ( Alacah ?? ) ( y ( ( ?? k ) ( near Ankara ) ) ) ) ) . )
(ROOT (S (S (NP (NP (NP (DT The) (NN advent)) (PP (IN of) (NP (NP (DT the) (NN Bronze) (NN Age)) (PRN (-LRB- -LRB-) (NP (QP (RB about) (CD 3200) (CD b.c.))) (-RRB- -RRB-))))) (, ,) (CC and) (NP (NP (DT the) (NN spread)) (PP (IN of) (NP (NP (NNS city-states)) (VP (VBN ruled) (PP (IN by) (NP (NNS kings))))))) (, ,)) (VP (VBZ is) (VP (VBN marked) (PP (IN by) (NP (NP (DT the) (NN appearance)) (PP (IN of) (NP (JJ royal) (NNS tombs))))) (S (VP (VBG containing) (NP (NN bronze) (NNS objects)) (PP (IN in) (NP (JJ such) (NNS places))) (PP (IN as) (NP (NP (NNP Troy)) (PP (IN in) (NP (DT the) (NN west)))))))))) (, ,) (CC and) (S (NP (NNP Alacah) (NNP ??)) (VP (VBP y) (NP (NP (JJ ??) (NN k)) (PP (IN near) (NP (NNP Ankara)))))) (. .)))
We know the Bronze Age started around 3200 b.c. because royals were starting to be buried with bronze treasure.
( We ( ( know ( ( the ( Bronze Age ) ) ( ( started ( around ( 3200 b.c. ) ) ) ( because ( royals ( were ( starting ( to ( be ( buried ( with ( bronze treasure ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP We)) (VP (VBP know) (SBAR (S (NP (DT the) (NN Bronze) (NN Age)) (VP (VBD started) (PP (IN around) (NP (CD 3200) (NN b.c.))) (SBAR (IN because) (S (NP (NNS royals)) (VP (VBD were) (VP (VBG starting) (S (VP (TO to) (VP (VB be) (VP (VBN buried) (PP (IN with) (NP (NN bronze) (NN treasure))))))))))))))) (. .)))