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 fire requires oxygen to burn. 
Fact 2: There is no "gaseous" oxygen on the Moon and the Moon itself is bone dry.

SOLUTION: A fire is cannot burn naturally above the surface of the Moon.

PROBLEM: Fact 1: planting trees has a positive impact on an ecosystem. 
Fact 2: Biodiversity encourages a healthier ecosystem.

SOLUTION: planting trees has a positive impact on biodiversity.

PROBLEM: Fact 1: Birth may be followed by a period of parental care of the offspring. 
Fact 2: Parents teach their offspring to feed and to avoid danger.

SOLUTION:
Birth may be followed by parents teaching their kids to feed and avoid danger.