How can you tell that Vincent van Gogh’s self-portrait is in realistic proportion?

To make an etching the artist first coats the entire printing plate with an acid-resistant substance called a made from beeswax, asphalt, and other material. the artist then draws on the coated plate with an etching needle exposing the metal. next the plate is dipped in the plate is removed, the waxy coating removed, and the plate is cleaned, inked and printed.

Sound waves can travel only in the aira. trueb. false

For the difference command to work, what needs to happen?