instruction:
Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.
question:
Fact: combining an egg and sperm increases genetic diversity. 
Question: what increases genetic diversity?
answer:
combining egg and sperm.


question:
Fact: Heating with coal can cause air pollution. 
Question: Heating with coal can cause?
answer:
air pollution.


question:
Fact: Blood pH may become unbalanced if the lungs are working too fast or too slow. 
Question: What may become unbalanced if the lungs are working too fast or too slow?
answer:

blood pH.