  The {\it string theory} seems to be a mathematically consistent way for
explaining so far observed fermion and boson second quantized fields, with
gravity included, by offering the renormalizability of the theory by extending
the point fermions and bosons into strings and by offering the supersymmetry
among fermions and bosons. In a long series of works one of the authors in
collaboration with another author and other collaborators, has found the
phenomenological success with the model named the {\it spin-charge-family}
theory with the properties: The creation and annihilation operators for
fermions and bosons fields are described as tensor products of the Clifford odd
(for fermions) and the Clifford even (for bosons) ``basis vectors'' and basis
in ordinary space, explaining the second quantization postulates. The theory
offers the explanation for the observed properties of fermion and bosons and
for several cosmological observations. Since the number of creation and
annihilation operators for fermions and bosons is in this theory the same,
manifesting correspondingly a kind of supersymmetry, the authors start to study
in this contribution the properties of the creation and annihilation operators
if extending the point fermions and bosons into strings, expecting that this
theory offers the low energy limit for the {\it string theory}.
