Diego wants to see if a natural mosquito is more effective than synthetic (man made) Repellent. (HELP PLS ASAP) Indenpendent variable :
Dependent variable :
Controlled variables :

(science not english)

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.

the sentence that avoid faulty coordination is:

culture, which is well represented in philadelphia, plays a major role including theatre, music, and the visual arts.  

faulty coordination occurs when the writer gives equal importance two different ideas (clauses) which in fact are not equivalent. in order to correct a misplaced clause or idea, the writer can place less important or emphatic ideas in a relative clause as in the previous sentence.  

the eye wink at the hand; yet let that be / which the eye fears, when it is done, to see.