所以 is read as ゆえん (yuen) and means reason.
ゆえん
yuen
ところどころ
here and there
しょとく
income
しょゆう
one's possessions
ところ
address
しょさ
conduct
しょちょう
head (of an office, laboratory, etc.)
しょじ
possession
しょてい
prescribed
しょしん
belief
しょざい
whereabouts
しょゆうけん
ownership
しょけん
view