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: eating food that contains pesticides can have a negative impact on humans. 
Fact 2: Foods such as porous strawberries are hard to wash free of pesticides.
Example Output: Eating unwashed strawberries can have a negative impact on humans.

Example Input: Fact 1: fire converts chemical energy into light and heat energy. 
Fact 2: Fuel is considered a chemical energy.
Example Output: Fuel converts into light and heat.

Example Input: Fact 1: a rainbow is formed by refraction of light by separating light into all different colors. 
Fact 2: Rainbows Rainbows are important symbols to the Navajo people.
Example Output:
Important symbols to the Navajo people are formed by refraction of light by separating light into all different colors.