v .
to break down ; to deteriorate 쇠퇴하다 ; 타락하다

• The discussion quickly _____d into an argument.
  토론은 급속도로 말싸움으로 변질되었다.
• Over the years, the nice old neighborhood had _____d into a terrible slum.
  수년에 걸쳐, 깨끗하고 고풍스런 동네는 끔찍한 빈민가로 변질되었다.
• The fans' behavior _____d as the game went.
• A person whose behavior has _____d can be referred as a _____. The mood of the party was spoiled when a drunken _____ wandered in from off the street.
• _____ can also be an adjective, meaning _____d. The slum neighborhood was _____. The fans' _____ behavior prompted the police to make several arrests.