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: lungs are used for breathing air by land animals. 
Fact 2: African Elephants are the biggest land animals.

SOLUTION: african elephants have lungs.

PROBLEM: Fact 1: infection can cause bodily tissues to swell. 
Fact 2: Bacteria can cause infection.

SOLUTION: Bacteria can cause bodily tissues to swell.

PROBLEM: Fact 1: Animals can communicate with sounds, chemicals, or visual cues. 
Fact 2: Communication requires an idea, a message to share.

SOLUTION:
animals share ideas with sounds, chemicals or visual cues.