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: x-rays are used in oncology. 
Question: what are used in oncology?

Answer: x-rays.


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

Answer: newer.


Question: Fact: melting is when something part of a colloidal system is heated above its melting point. 
Question: Melting is when something that is part of what is heated above its melting point?

Answer:
colloidal system.