When donovan was four years old, he was startled and began to cry when a car backfired just as he was walking past a fire hydrant. as an adult, donovan is still fearful of fire hydrants and avoids walking near them. based on principles of classical conditioning, donovan's current fear of fire hydrants is?

Based on principles of classical conditioning, Donovan's current fear of fire hydrants is​ "a conditioned response".

An conditioned response refers to a conduct that does not easily fall into place, but rather should be learned by the person by blending a nonpartisan boost with a strong stimulus. The powerful stimulus is one that does not require any learning or molding to react to fittingly. 

The  ancient egyptians  who  built the pyramids  may have been  able  to move massive stone blocks across the desert by wetting the sand in front of a contraption  built  to pull the heavy objects