Answer: C. 30 - 50 million years ago
Explanation:
Fossils found in layer Y formed 30 million years ago according to the graph above. Similarly, fossils found in layer Z formed 50 million years ago.
If a fossil (fern fossil) is found between layer Y and layer Z, it means that it formed between the years that the fossils in layers Y and Z formed which is 30 - 50 million years ago.
In order for gas to leave a planet it needs to be hot enough and to overcome the planets gravity. The outer planets are colder and are very big compared to earth.
Kelp is very sensitive to temperature change. Placing the plant near the window and exposing it to direct sunlight will result in continuous warming of the water in which the kelp plant is growing. Research has shown that kelp plant degrades very quickly when temperature increases due to tissue loss.
Testable and rejectable.
Recorded data may be quantitative or qualitative.
