  Ever since its birth, up until its present development, the major role of
string theory involves being the best candidate for the theory of quantum
gravity and other species of interactions. In the present work, we would like
to accomplish this goal by minimally extending its content while greatly
simplifying its structure. To be more specific, by endowing the closed
superstring with its spin, we successfully achieve this goal. This issue has
been addressed in the first part of this work, entitled, "mission 1 of the
work". In addition, we would like to make further developments on the selection
of compactification manifolds that brings the string theory from the critical
10 dimensions down to four cosmology dimensions. Indeed, this issue has not
been fully seriously and extensively explored in the literature. In the present
work, therefore, we want to bring serious attention to this missing but
non-trivial issue. This issue has been addressed in the second part of this
work, entitled, "mission 2 of the work".
