TASK DEFINITION: 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.
PROBLEM: Fact 1: a flashlight requires a source of electricity to produce light. 
Fact 2: Flashlights and remote controlled cars get their energy from batteries.

SOLUTION: cars use electricity.

PROBLEM: Fact 1: refracting sunlight causes sunlight to split into different colors. 
Fact 2: When Sunlight passes through a prism, the light is separated into a rainbow of different colors.

SOLUTION: Refracting sunlight causes sunlight to split into colors and form a rainbow.

PROBLEM: Fact 1: Mutations are essential for evolution to occur. 
Fact 2: Viruses can cause a mutation in a gene.

SOLUTION:
viruses can cause evolution to occur.