A ja bym proponował inne umiejscowienie przecinków:
Zamiast
"In Poland, the decreasing tendency in teachers employment due to demographical changes, is observed. That's the reason why a lot of
teachers may be expected to lose their workplaces in the future",
In Poland the decreasing tendency in teachers employment, due to
demographical changes, is observed. That's the reason why a lot of
teachers may be expected to lose their workplaces in the future.
Takie umiejscowienie wydaje się być logiczniejsze, gdyż gdy usuniemy zdanie wtrącone, nadal zdanie jest zrozumiałe:
In Poland the decreasing tendency in teachers employment is observed.
Pozdrawiam