你从哪里看到Transylvania是二战后加入的？据我所知，是一战后从奥匈帝国割的

根据AI：Transylvania became part of Romania in stages, with the key moment being the declaration of union on December 1, 1918, after World War I, formally ratified by the Treaty of Trianon in 1920, which officially transferred the region from Hungary to Romania, though parts were temporarily returned to Hungary during WWII before becoming definitively Romanian post-war