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: Mammals generate heat mainly by keeping their metabolic rate high. 
Fact 2: Humans use food to generate body heat.

SOLUTION: food keeps mammals' metabolic rates high.

PROBLEM: Fact 1: thick fur can be used for keeping warm. 
Fact 2: With a thick fur coat and 4 inches of fat a bear stays warm.

SOLUTION: Bears have thick fur to protect from the cold.

PROBLEM: Fact 1: photosynthesis means producers convert from carbon dioxide, water, and solar energy into carbohydrates for themselves. 
Fact 2: Producers are organisms, such as green plants, that convert light energy into food.

SOLUTION:
green plants convert carbon dioxide, water, and solar energy into carbohydrates for themselves.