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 gravitational pull of the Moon on Earth 's oceans causes the tides. 
Fact 2: Tides create current.

A: The gravitational pull of the Moon on Earth's ocean contributes to ocean currents.
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Q: Fact 1: Energy is passed up a food chain or web from lower to higher trophic levels. 
Fact 2: Plants represent the first trophic level.

A: Energy is passed up a food chain from plants.
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Q: Fact 1: Bile reduces the acidity of food entering from the highly acidic stomach. 
Fact 2: Subjects include acids and bases, oxidation and reduction, chemical equilibrium and thermodynamics.

A:
Bile acts as a base on the food entering the stomach.
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