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: faulting of rock in Earth 's crust causes earthquakes. 
Fact 2: Earthquakes generate P waves and S waves which can travel throughout the earth.
Example Output: P-waves and S-waves can be traced back to faulting of rock in Earth's crust.

Example Input: Fact 1: hitting an object causes the particles in that object to vibrate. 
Fact 2: Sounds are caused by vibrations.
Example Output: hitting an object causes Sounds.

Example Input: Fact 1: measuring the hardness of minerals requires scratching those materials. 
Fact 2: Carbonate minerals, such as malachite, pearl, and rhodochrosite, are damaged by chemical attack.
Example Output:
measuring the hardness of a pearl requires scratching it.