| A | B |
|---|
| adulthood | the period of greastest strength and stamina |
| puberty | the physical changes during adolescence |
| prenatal | time before birth |
| growth spurt | time of rapid change |
| infancy | the second stage of growth |
| heredity | passing traits from a parent |
| cartilage | soft rubbery material |
| endocrine system | sends messages around the body |
| muscles | responsible for body movement |
| divorce | a difficult change |
| negotiate | resolving conflicts with give and take |
| volunteer | give time and energy, no pay |
| responsible | you can be depended on |
| empathy | understanding how another person feels |
