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: most canyons are formed by flowing rivers through erosion over long periods of time. 
Fact 2: Erosion was monitored by means of erosion pins.
Example Output: Canyon changes are tracked with pins.

Example Input: Fact 1: pollutants have a negative impact on the environment. 
Fact 2: Incineration is harmful to the environment, it pollutes.
Example Output: inceneration is harmful to the environment.

Example Input: Fact 1: the force of water against the seed coat causes a root to emerge from a seed. 
Fact 2: Acorns are the seeds of oak trees.
Example Output:
water causes a root to emerge from an acorn.