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.

Fact 1: completing a circuit causes electricity to flow through that circuit. 
Fact 2: Electricity can give the opener a shock.
completing a circuit can give someone a shock.

Fact 1: pesticides can cause pollution. 
Fact 2: Air pollution harms the ecosystem.
pesticides can harm the ecosystem.

Fact 1: if the amount of available food and water decreases in an environment then animals may leave that environment to find food and water. 
Fact 2: When wild animals no longer find their own food, they cease to be a part of the balance of nature.

If the amount of available food and water decreases in an environment, the animals cease to be a part of the balance of nature.