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.

Q: Fact 1: the surface of a beach is formed by mechanical weathering. 
Fact 2: Beaches and Sand Dunes Dunes are accumulations of sand blown from the beach by the wind.

A: sand formations are formed by wind.
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Q: Fact 1: coal is used for generating heat by burning. 
Fact 2: Thus, the food is cooked by heat generated internally.

A: coal can be used to cook food.
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Q: Fact 1: if an object is black then that object absorbs all visible light. 
Fact 2: Visible light is made up of all the colors of the spectrum.

A:
A black object absorbs all of the colors of the spectrum.
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