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: Roundworms reproduce sexually. 
Fact 2: Nematodes are simple roundworms.

SOLUTION: nematodes reproduce sexually.

PROBLEM: Fact 1: Urine leaves the body through a sphincter in the process of urination. 
Fact 2: Fluids in the urine eliminate metabolic waste products.

SOLUTION: Metabolic waste products can leave the body through a sphincter.

PROBLEM: Fact 1: an automobile engine transforms chemical energy into mechanical energy. 
Fact 2: Mechanical energy is the energy of moving objects.

SOLUTION:
An automobile engine transforms chemical energy into moving objects.