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: Most invertebrates have a more complex nervous system. 
Fact 2: Cephalopods have the most advanced nervous systems of all invertebrates.
answer:
Cephalopods have a complex nervous system.


question:
Fact 1: most canyons are formed by flowing rivers through erosion over long periods of time. 
Fact 2: Erosion was monitored by means of erosion pins.
answer:
Canyon changes are tracked with pins.


question:
Fact 1: Pregnancy is the carrying of one or more offspring from fertilization until birth. 
Fact 2: An elephant pregnancy lasts about 22 months.
answer:

An elephant carries their offspring from fertilization until birth, 22 months later.