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: Nonmetal elements are far fewer in number. 
Fact 2: Most of the elements on the periodic table are nonmetals.
answer:
Most of the elements on the periodic table are far fewer.


question:
Fact 1: Mollusks are invertebrates such as the common snail. 
Fact 2: Invertebrates have no backbone.
answer:
mollusks have no backbone.


question:
Fact 1: Mammals generate heat mainly by keeping their metabolic rate high. 
Fact 2: Humans use food to generate body heat.
answer:

food keeps mammals' metabolic rates high.