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: Fault zones are plates in the earth that slide and collide.
Example Output: plates in the earth collide which causes earthquakes.

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: moss causes chemical weathering. 
Fact 2: Mosses lack the roots and stems that other plants have.
Example Output:
Plants lacking roots and stems cause chemical weathering.

