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: soil is formed by weathering. 
Fact 2: Soils are formed by breakdown of rock.

Ex Output:
Weathering is the breakdown of rock.


Ex Input:
Fact 1: a breathing mask is used for keeping harmful particles from entering the respiratory system. 
Fact 2: When mold grows in the house, it can emit particles that travel through the air.

Ex Output:
A breathing mask can keep mold from entering the respiratory system.


Ex Input:
Fact 1: Ozone depletion results in higher levels of UV radiation reaching Earth. 
Fact 2: Birds live on Earth, trees live on Earth.

Ex Output:

ozone depletion results in higher levels of uv radiation reaching the place birds and trees live.