1. Because the pace of life continues to increase. (Or: Because they become busier than ever before.)
2. Not being afraid of stress. (Or: Knowing the art of relaxation.)
3. the choice between "flight or fight".
4. When the stress is out of control. (Or: When we are exposed to stress for too long a time.)
5. Try to cope with it. (Or: To find ways to deal with it.)