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: Flagella help prokaryotes move. 
Fact 2: Some species swim by means of flagella Bacterial flagella are analogous to flagella of eukaryotes.

SOLUTION: prokaryotes and Bacteria move by swimming.

PROBLEM: Fact 1: fossils are formed when layers of sediment cover the remains of organisms over time. 
Fact 2: All streams carry sediment .

SOLUTION: Fossils are formed when layers of something streams carry cover the remains of organisms over time.

PROBLEM: Fact 1: Food is easier to chew because it is moistened by saliva from the salivary glands. 
Fact 2: Salivary Gland Cancer Salivary glands are located throughout the oral cavity.

SOLUTION:
Food is easier to chew because it is moistened by saliva from throughout the oral cavity.