crices of 17 years old

crises of 17 years old
why zone of young men around 17 years old have been triggered into the crime of sadness incidents into society.
one of reasons might be considered that be driven too much competition of university
entrance exams that means effect of too much stress to the youth in terms of mental and physical view who turn to the decision period of their future at that time.
please imagine the screw which consist of bolts and nuts.
for the screw ,bolt and nut production,first process of heat treatment after forming shape of bolts and nuts from steel wire. at first process screw will be heated into chamber of high temperature 800℃ what we call temper proses this status make screwｓ harder surface、however its inside is in weak and fragile status .
to be continued