根据短文内容，完成下列各题。
Puberty (青春期) is the stage of life when young people leave childhood and head into adulthood. It is a difficult process (过程) for teenagers because it has an effect on both their minds and bodies. They need to understand what is going on with their bodies, how to deal with those changes and how to start taking responsibility (责任) for themselves.
A young person may begin puberty at 8, while another may not start puberty (A) _________14 or 15. In general, girls start puberty two years before boys do. For both girls and boys, it is usually complete by the age of 18.
During these years, the body develops in many ways. (B)感受也会迅速地改变。
Teenage boys at this stage often begin to take unnecessary risks. Their focus is on having fun and being accepted by others. (C)Theyneed to think before they act and make good decisions for themselves.
A girl's personality often does not develop in the same way (D) __________a boy's. Teenager girls sometimes lose confidence in themselves. They are no longer (E)certainabout their own feelings. Yet they are usually afraid to tell their parents or teachers about their problems. For this reason, teenage girls should be encouraged to (F)talk aboutthings with trusted adults.
Parents, schools and communities can do a lot to care for and help young people. It is everyone's responsibility to make sure that young people grow into healthy adults.