TASK DEFINITION: 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.
PROBLEM: Fact 1: if a planet becomes too hot then that planet cannot sustain life. 
Fact 2: Life depends to a large degree on the temperature of the planet, and temperature depends in part on the distance of the planet from the sun.

SOLUTION: Life cannot be sustained above a certain temperature.

PROBLEM: Fact 1: Constriction occurs when the muscular walls of blood vessels contract. 
Fact 2: Dehydration causes vessels to constrict and blood to thicken.

SOLUTION: Constriction causes blood to thicken.

PROBLEM: Fact 1: Evolution is a change in the characteristics of living things over time. 
Fact 2: An organism is a living thing.

SOLUTION:
evolution is a change in the characteristics of organisms over time.