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.

Ex 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.

Ex Output:
P-waves and S-waves can be traced back to faulting of rock in Earth's crust.


Ex Input:
Fact 1: Phylogeny is the evolutionary history of a group of related organisms. 
Fact 2: Classification can be based on phylogeny.

Ex Output:
classification can be based in the evolutionary history of a group of related organisms.


Ex Input:
Fact 1: vein deposits of gold and silver are formed by igneous intrusion. 
Fact 2: Magma that cools slowly deep below the surface produces coarse-grained intrusive igneous rocks.

Ex Output:

Vein deposits of gold and silver are formed when magma cools.