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: when a hemisphere is tilted away from the sun , that hemisphere receives less direct sunlight. 
Fact 2: With less sunlight, the forest is cooler and wetter.

SOLUTION: When a hemisphere tilts away from the sun, the forests there become cooler and wetter.

PROBLEM: Fact 1: changes in the pH of soil can cause plants to die. 
Fact 2: Sulfur lowers pH in soil.

SOLUTION: Adding sulfer to soil can cause plants to die.

PROBLEM: Fact 1: a plant requires sunlight to grow. 
Fact 2: Still it takes about eight minutes for sunlight to travel from the sun to the earth.

SOLUTION:
A plant requires something that takes eight minutes to travel to the Earth to grow.