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: Weather refers to the conditions of the atmosphere from day to day. 
Fact 2: Earth's Atmosphere Earth's atmosphere is the layer of gasses that surrounds the earth.
weather refers to the conditions in the layer of gasses that surrounds the earth.

Fact 1: conserving resources has a positive impact on the environment. 
Fact 2: Humans meet some needs and wants by using resources found in the natural environment.
Humans have a negative impact on the environment.

Fact 1: when a gas in an open container evaporates , that gas spreads out into the air. 
Fact 2: Similarly, hydrogen is an explosive gas.

when hydrogen evaporates from an open container, it spreads out into the air.