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.

Fact: AIDS infects and destroys helper T cells. 
Question: what infects and destroys helper T cells?
AIDS.

Fact: Plants are essential for cellular respiration for all aerobic organisms. 
Question: What is essential for cellular respiration for all aerobic organisms.?
Plants.

Fact: Viruses often infect something killed by antibiotics. 
Question: Viruses often infect something killed by what?

Antibiotics.