instruction:
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.
question:
Fact 1: a delta is formed by deposition of sediment at the mouth of a river by water fanning out. 
Fact 2: Rivers provide a water supply.
answer:
a delta is formed by deposition of sediment at the mouth of a water supply fanning out.


question:
Fact 1: Biodiversity generally increases from the poles to the equator. 
Fact 2: Soil Biodiversity Soil biodiversity reflects the mix of living organisms in the soil.
answer:
the mix of living organisms generally increases from the poles to the equator.


question:
Fact 1: Food is easier to chew because it is moistened by saliva from the salivary glands. 
Fact 2: Feeds are mixed with saliva in the mouth to make a moist bolus that can be easily swallowed.
answer:

a bolus is moistened food.