So all we know is that the student stated something ("<span>if plants are added to an indoor environment the air quality will improve
"). This is only a statement - it's not a test whether this statement is true yet.
So the correct answer is: it is a hypothesis.
</span>
Answer:
the correct answer would be
A. atoms, molecules, cells, tissues, organs
Nutrients are delivered by the blood through the capillary network.
