Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.

Example Input: Fact 1: Cells have multiple repair mechanisms to fix mutations in DNA. 
Fact 2: And if the damaged DNA is duplicated, it causes mutation.
Example Output: Cells have multiple repair mechanisms to fix damaged DNA duplication.

Example Input: Fact 1: a prism is used for refracting light. 
Fact 2: Refraction is the bending of a ray of light.
Example Output: A prism can be used to bend a ray of light.

Example Input: Fact 1: a calculator is used for adding. 
Fact 2: Calculator Use an online calculator.
Example Output:
adding can be done online.