1- The relationship is:
classification and type.
"Difference" is how you classify or categorize what happens between two words or ideas. What kind or type of difference is it? Answer: "Opposite". For example, what is the relationship between the adjectives "happy" and "sad"? Answer: difference. What type of difference? Answer: "happy" is the opposite of "sad" and vice-versa.
2- The analogy goes like this:
police officer:patrol car/ dentist: drill
We are talking about certain tools the professionals mentioned need in order to perform their jobs.
3- The analogy goes like this:
photograph:memory/ recipe: food
A photograph makes a memory come to life, and a recipe is necessary to make food come to life.
4- The analogy goes like this:
Romeo and Juliet: drama/ Happy Birthday to You: music
.
"Romeo and Juliet" is a play. Thus, it belongs to the drama category (art).
"Happy Birthday to You" is a song. Thus, it belongs to the music category (art).
