For any generalized ordered space X with the underlying linearly ordered topological space Xu, let X* be the minimal closed linearly ordered extension of X and be the minimal dense linearly ordered extension of X. The following results are obtained.
(1) The projection mapping π:X*→X, π(〈x,i〉)=x, is closed.
(2) The projection mapping , ϕ(〈x,i〉)=x, is closed.
(3) X* is a monotone D-space if and only if X is a monotone D-space.
(4) is a monotone D-space if and only if Xu is a monotone D-space.
(5) For the Michael line M, is a paracompact p-space, but not continuously Urysohn.