[Q]: Sentence: It is unclear why the Chinese did not press the attack and follow up their victory. Question: What is unusual about the PVA's successful, surprise attack?
++++++++++
[A]: no

[Q]: Sentence: However, the Council began with only four permanent membersthe United Kingdom, France, Italy, and Japanbecause the United States, meant to be the fifth permanent member, left because the US Senate voted on 19 March 1920 against the ratification of the Treaty of Versailles, thus preventing American participation in the League. Question: When did US Senate vote against treaty of versailles ratification?
++++++++++
[A]: yes

[Q]: Sentence: Saint Athanasius of Alexandria (/nes/; Greek: , Athanasios Alexandrias; c. 296298 2 May 373), also called Athanasius the Great, Athanasius the Confessor or, primarily in the Coptic Orthodox Church, Athanasius the Apostolic, was the twentieth bishop of Alexandria (as Athanasius I). Question: Of what city was he bishop?
++++++++++
[A]:
yes