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: plants are sensitive to darkness. 
Question: What are plants sensitive to?
darkness.

Fact: suspension bridges are newer types of bridges. 
Question: suspension bridges are considered to be what design wise?
newer.

Fact: Fossils are remnants of ancient life. 
Question: What ancient life remnants are studied?

fossils.