TASK DEFINITION: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
PROBLEM: Question: Which of the following has changed over the last 200 years primarily due to human activity? Answer: the composition of the atmosphere

SOLUTION: The composition of the atmosphere has changed over the last 200 years primarily due to human activity.

PROBLEM: Question: The fact that water in a reservoir is elevated above the ground means that it has what kind of energy? Answer: potential

SOLUTION: The fact that water in a reservoir is elevated above the ground means that it has potential kind of energy.

PROBLEM: Question: What type of ions play critical roles in light-dependent reactions? Answer: hydrogen

SOLUTION:
Hydrogen type of ions play critical roles in light-dependent reactions.