Ways society can be affected by stds or stis are sexual contact, and the mixing of bodily fluids such as blood, spit (in some stds or stis), sweat (only in some stds or stis), urine, etc.
The answer to this question is called communication
People who are sad because of some one that died
People who have went through a broken heart
Orphans
Homeless
People who became hit by bad news
People who are lonely
People who never have someone to cheer them up.
Calories, you need calories to function. calories are found in food.