Idk the answer, I'm sorry
Well there's Water, Earth, Fire, and Air. Not quite sure how this would be a school question. But here it is.
Length of time candle burns is the correct answer.
If you use chemicals to kill insects, you could risk getting the chemicals in unwanted areas. This could kill plants, animals, and other living things. You could also contaminate water if the chemicals get rinsed/drained into a water source.
