Photo taken on Dec. 10, 2019 shows the scene of 3D projection on the facade of the Greek Parliament during a tree lighting ceremony on Syntagma Square in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)

Photo taken on Dec. 10, 2019 shows the scene of 3D projection on the facade of the Greek Parliament during a tree lighting ceremony on Syntagma Square in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)

Photo taken on Dec. 10, 2019 shows the scene of 3D projection on the facade of the Greek Parliament during a tree lighting ceremony on Syntagma Square in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)

Photo taken on Dec. 10, 2019 shows the scene of 3D projection on the facade of the Greek Parliament during a tree lighting ceremony on Syntagma Square in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)

Photo taken on Dec. 10, 2019 shows a general view of the Syntagma Square decorated for the Christmas season in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)

Photo taken on Dec. 10, 2019 shows a general view of the Syntagma Square decorated for the Christmas season in Athens, Greece. The festive season kicked off in Athens with the tree lighting ceremony on Syntagma Square on Tuesday. (Xinhua/Marios Lolos)