How is the invention of the nail, useful today?

Opera combines music with which of the following

Blind contour line drawings are : a. often used to paint landscapes b. often detailed but not perfect c. often detailed and flawless

In this unit, it is mentioned that in order to enter into the field of photography, most jobs require at least a high school degree. since there is a possibility you can attain one of these jobs with just finishing high school, why do some people get an associates or bachelor’s degree?