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.

Fact 1: All plants have a characteristic life cycle that includes alternation of generations. 
Fact 2: Plants have chlorophyll and an alternation of generations .
Plants have chlorophyll and a characteristic life cycle.

Fact 1: Nonmetal elements are far fewer in number. 
Fact 2: Most of the elements on the periodic table are nonmetals.
Most of the elements on the periodic table are far fewer.

Fact 1: burning fossil fuels increases the carbon in the atmosphere. 
Fact 2: Carbon dioxide is produced by the burning of fossil fuels such as coal, oil and natural gas.

Burning coal, oil, and natural gas increases carbon in the atmosphere.