Answer:
I'm sorry. I wanted to try and answer the question but I can't because it isn't clear.
Answer:
You can't see the blood vessels themselves because vision depends on a process that makes it impossible to see things that are stationary with respect to the retina. Light receptors in the retina respond only to changes in light reaching them, not to a steady image.
Have a great day! :D
Answer: after organelles it cells,tissues,organs,organ system then it give you the last one which is organism.
Explanation:
I would say it's A because it sounds like the most important one.
The answer would only betertiary consumer