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: pushing on the pedals of a bike cause that bike to move. 
Fact 2: First, overcoming inertia to move forward is difficult.
answer:
Pushing on bike pedals cause the bike to overcome inertia.


question:
Fact 1: breaking apart rocks can cause debris. 
Fact 2: Sledge hammers can be used to break especially hard ledges of rock.
answer:
hammers can cause debris.


question:
Fact 1: high pressure systems cause clear weather. 
Fact 2: High pressure systems push air closer to the ground, preventing the formation of clouds.
answer:

Clear weather occurs when air is pushed closer to the ground.