8. 已知函数f(x)=ax5+bx3+cx+1(abc≠0)f(x)=ax^{5}+bx^{3}+cx+1(abc\ne 0)f(x)=ax5+bx3+cx+1(abc=0),若f(−2)=5f(-2)=5f(−2)=5,则fff(2)=(=(=( )))