List a few reason why the oxygen level decreases in the cave.

Lack of circulation, lack of plants

Explanation:

Oxygen levels decrease in caves because if a person is inside they are using up the oxygen and repalcing it with carbon dioxide with only a small entrance for new oxygen to come inside.  Additionally, the lack of sunlight inside a cave means that plants can not go through photosynthesis and survive, so no plants can create the oxygen inside the cave.

i believe the answer is:   psychological  experiment

in this experiment, wilhelm wundt became the first person that implement scientific method in analyzing the pyschological phenomenon.

due to this result, wilhelm wundt also able to make psychology to be acknowledged as a separate scientific field from biology.

answer; genetics;