instruction:
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.
question:
Fact 1: fossils are formed when layers of sediment cover the remains of organisms over time. 
Fact 2: All streams carry sediment .
answer:
Fossils are formed when layers of something streams carry cover the remains of organisms over time.


question:
Fact 1: an egg requires warmth to survive. 
Fact 2: Heat and warmth help other gift plants.
answer:
an egg requires heat to survive.


question:
Fact 1: Complex chemistry is needed to carry out all the functions of life. 
Fact 2: Genes control the complex chemistry of the body and are passed on from patients to their children.
answer:

Genes control what is needed to carry out all the functions of life.