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: a warm front causes cloudy and rainy weather. 
Fact 2: Behind the warm front are thick, low stratus clouds and possibly more rain.
Example Output: cloudy and rainy weather is accompanied by stratus clouds.

Example Input: Fact 1: Complex chemistry is needed to carry out all the functions of life. 
Fact 2: Life functions of cell growth and reproduction are seen.
Example Output: Complex chemistry is needed to carry out cell growth and reproduction.

Example Input: Fact 1: Muscles can only contract. 
Fact 2: Bones work with muscles to perform movement.
Example Output:
Contraction enables bones to perform movement.