Answer:
Here are a few examples:
Volcanic eruptions.
Retreat of glaciers.
Flooding accompanied by severe soil erosion.
Landslides.
Nuclear explosions.
Oil spills.
Abandonment of a manmade structure, such as a paved parking lot.
Explanation:
Measuring photosynthesis via the production of oxygen. Oxygen can be measured by counting bubbles evolved from pondweed, or by using the Audus apparatus to measure the amount of gas evolved over a period of time.
Answer:
The control variable is the soldier.
Explanation:
The same soldier is used throughout the test
