The independent variable is the different amount of repellent each person is given. This is because it does not depend on any variable. The dependent variable is what they are measuring, which would be the number of bites on each volunteer.
I hope this helps! :)
There are none on the list you included with your question.
Answer:
thick wire and cold temperatures
Hydroelectric power. That's just the term for electricity gained by using water, think of a water mill.
