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: rocks interacting with wind over long periods of time causes weathering. 
Fact 2: Rocks weather at different rates.
answer:
wind affects rocks.


question:
Fact 1: Nephrons are the structural and functional units of the kidneys. 
Fact 2: Finally, the fluid in the nephron reaches a collecting duct .
answer:
fluid in the kidneys collect into ducts.


question:
Fact 1: DNA replication is the process in which DNA is copied. 
Fact 2: DNA DNA is deoxyribonucleic acid.
answer:

deoxyribonucleic acid replication is the process in which deoxyribonucleic acid is copied.