The thesis has been conducted in Hanoi, one of two economic – cultural – political centers of Vietnam. Moreover, Hanoi is the largest centre of education in Vietnam with a variety of reputable and ancient universities. In addition, almost every lecture in these universities comes from various pronvinces in the North of Vietnam, which creates the variety in custome, culture, habits and lifestyle in comparison with lectureres in other areas. Hence, the conduct of this study in Hanoi will be more consistent.
