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.

Ex Input:
Fact: Vertebrates are all chordates that have a spinal column. 
Question: What do all vertebrates have that invertebrates don't?

Ex Output:
a spinal column.


Ex Input:
Fact: Hummingbirds co-evolved with plants. 
Question: Hummingbirds are what they are today as a necessary consequence of their relationship to what?

Ex Output:
Plants.


Ex Input:
Fact: Uneven heating of the Earth's surface causes destruction to homes and businesses. 
Question: Uneven heating of the Earth's surface causes what to homes and businesses?

Ex Output:

destruction.