Which of the following is the correct flow of oxygen in the human body? 1. oxygen moves from the alveolus and enters the blood stream to capillaries. 2. air moves down through the trachea to the lungs. 3. blood full of oxygen moves to the heart and then out to body cells. 4. breathing in air through nose and mouth. 5. air moves to alveolus in the lungs.

Because the author of the article did not do an experiment to draw his own conclusions and issue his own information, but he did a bibliographic review of the work of other authors to write his own article.

Explanation:

The article presented in the question above was done through a bibliography search and not through an experiment. This means that the author did not test the hypotheses through a scientific experiment, but formulated the conclusions of his article, based on the works of other authors, which makes this article not the best option to be considered as a reference article.