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.

Example Input: Fact 1: increasing heat causes thermal expansion. 
Fact 2: Motion helps to increase body heat.
Example Output: motion causes thermal expansion.

Example Input: Fact 1: Viruses cannot reproduce by themselves. 
Fact 2: Bats can also transmit rabies and rabies-like viruses.
Example Output: rabies cannot reproduce by itself.

Example Input: Fact 1: All chemical reactions require activation energy to get started. 
Fact 2: Basically, heat is energy.
Example Output:
All chemical reactions require heat to get started.