Complex sentence: According to Innis, it appears Greek colonies in Sicily and Italy and Greek traders introduced the Greek alphabet to Rome in the 7th century BC. The alphabet was developed into a Graeco-Etruscan script when Rome was governed by an Etruscan king.
Split into simpler sentences: According to Innis, it appears that Rome adopted the Greek alphabet from the Greek colonies in Sicily and Italy and from Greek traders. That happened, Innis writes, in the 7th century BC, when Rome was governed by an Etruscan king.