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: Mammals can also generate little bursts of heat by shivering. 
Fact 2: All humans are mammals.
humans can generate little bursts of heat by shivering.

Fact 1: Chromoplasts make and store pigments. 
Fact 2: Chromoplasts are found in many flower petals and fruits.
Flower petals and fruits make and store pigments.

Fact 1: a compass is used to navigate oceans. 
Fact 2: Navigation by compass is especially difficult during a magnetic storm.

Navigating the oceans can be more difficult during a magnetic storm.