Why would a butterfly fly away from a hiker? What is the advantage to this behavior? Are there potential disadvantages?

What are objects called that have value in and of themselves as well as value as a means of exchange? custom commodity money currency simple money

The two-factor theory of emotion was proposed by

In a study, people were asked to imagine simple occasions that made them happy and to remember events that made them feel proud about themselves. it was observed that the subjects developed an increasingly positive attitude. these changes are known to be healthy, leading to greater physical activity and reducing unhealthy habits. based on this excerpt, we can conclude that a positive attitude .