Answer:
Indenpendent variable : The type of mosquito repellent used
Dependent variable : How many mosquitoes land and bite
Controlled variables : The person (or people) using the repellent and the amount of repellent used. The number of mosquitos in the test area and the time of day, temperature, will also have to be controlled.
Explanation: The independent variable is the thing you are testing: natural vs synthetic repellent. The dependent variable is the effect or results you are measuring.
The control is making it a fair test, or valid experiment. If it is a cold afternoon in the spring in the city for one repellent and a warm summer evening by a pond in the woods for the other, it is obviously not a fair comparison of the effect of the type of repellent.
