Why should you not go to the back of a Spencers??? If ya know, ya know

Which of these is a consistent periodic pulse separated into equivalent intervals of time?

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

Artists best achieve contrast in a composition by: a. drawing with realism b. shading a drawing with dark and light values c. using drawing techniques like stippling and hatching d. focusing on line and shape in a drawing