exposition  
noun uk/ˌek.spəˈzɪʃ.ən/ us/ˌek.spəˈzɪʃ.ən/
  (EXPLANATION)      
  [ C or U ] formal清楚详尽的解释;详细阐述 
a clear and full explanation of an idea or theory
  It purports to be an exposition of Catholic social teaching. 它旨在详细阐述天主教的社会教义。 
 - More examples
 - They were awarded the gold medal for excellence at the Paris Exposition in 1900.
 - The Eastern States Exposition is held annually in Storrowtown Village.
 
  (SHOW)      
 [ C ] (also expo)展览会;博览会;商品交易会 
a show in which industrial goods, works of art, etc. are shown to the public
  the San Francisco exposition 旧金山博览会 
 Expo 92 (= a show that happened in 1992) 1992年博览会