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.


[Q]: Fact 1: Mammalian teeth are important for digestion. 
Fact 2: For instance, bacteria in the digestive tract helps glean the most nutrients from food.
[A]: Mammalian teeth are important for gleaning nutrients from food.


[Q]: Fact 1: mechanical weathering is when rocks are broken down by mechanical means. 
Fact 2: Pysical weathering is the mechanical breakdown of rocks.
[A]:
Physical weathering is when rocks are broken down by means.