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: air pollution can cause the pH of soil to decrease. 
Fact 2: Acidity is measured with a pH meter or with pH paper strips.
Example Output: air pollution can cause the Acidity of soil to decrease.

Example Input: Fact 1: breaking apart rocks can cause debris. 
Fact 2: Sledge hammers can be used to break especially hard ledges of rock.
Example Output: hammers can cause debris.

Example Input: Fact 1: recycling reduces the resources needed to make something. 
Fact 2: All bottles are recyclable.
Example Output:
bottles can reduce resources used.