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 pan is used for cooking food by heating food in it on a stove. 
Fact 2: Heat pan, add cooking oil to pan.
answer:
cooking oil heats food.


question:
Fact 1: air pollution can cause the pH of soil to decrease. 
Fact 2: Acidity is measured with a pH meter or with pH paper strips.
answer:
air pollution can cause the Acidity of soil to decrease.


question:
Fact 1: when a hemisphere is tilted away from the sun , that hemisphere receives less direct sunlight. 
Fact 2: The less direct the sunlight, the colder the weather.
answer:

When a hemisphere is tilted away from the sun, the weather is colder.