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: heavy rains cause flooding. 
Fact 2: Hurricane rains can cause landslides and flash floods.

SOLUTION: flooding can cause landslides.

PROBLEM: Fact 1: plant reproduction requires pollination. 
Fact 2: Bees are necessary for pollination.

SOLUTION: plant reproduction requires bees.

PROBLEM: Fact 1: a doorbell converts electrical energy into sound. 
Fact 2: Hearing is the act of perceiving sound.

SOLUTION:
a doorbell converts electrical energy into what we hear.