Psychologists are talking of a period of (1) _______ adolescence, or emerging adulthood, but it is hard to say what makes one really an adult. One way to (2) _______ adulthood might be the (3) _______ of the body, but as a matter of fact, bodily (4) _______ can help little to define adulthood’s boundaries, because (5) _______ doesn’t start or stop at the same time for everyone. Graduations cannot mark the change rightly either. In fact, education, especially secondary and higher education have contributed to (6) _______ the transitory period between childhood and adulthood. Science shows that human brain matures at about age 22 or 23. This finding (7) _______ well with what has been established as a sort of institutionalized transition time. Many countries in the world value highly “the Big Three” criteria: (8) _______ , (9) _______ , and (10) _______ .