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: completing a circuit causes electricity to flow through that circuit. 
Fact 2: Electricity can give the opener a shock.
Example Output: completing a circuit can give someone a shock.

Example Input: Fact 1: the volume of an object can be used to describe the size of that object. 
Fact 2: Mass and volume are the same thing.
Example Output: the mass of an object can be used to describe the size of that object.

Example Input: Fact 1: Male dogs use pheromones in urine to mark their territory. 
Fact 2: Pheromones are chemicals produced by insects to communicate.
Example Output:
male dogs use chemicals in urine to mark their territory.