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: Mammals generate heat mainly by keeping their metabolic rate high. 
Fact 2: Humans use food to generate body heat.
Example Output: food keeps mammals' metabolic rates high.

Example Input: Fact 1: the ovaries are used in reproduction. 
Fact 2: Infertility is a disease of the reproductive system that prevents the conception of children.
Example Output: The ovaries are used to have children.

Example Input: Fact 1: Many nucleotides bind together to form a chain called a polynucleotide. 
Fact 2: RNA like DNA is a polynucleotide.
Example Output:
Many nucleotides bind together to form DNA.