Viruses are considered to be non living things because they do not meet many of the criteria that are needed for an organism to be considered a living thing.
Viruses can not replicate on their own, they do not excrete any waste and do not meet all the seven features that living things must exhibit.
<h2>Answer:</h2><h3>1. Hepatitis B </h3><h3>2. Levels of circulating antibodies against a certain antigen.</h3><h2>Explanation:</h2><h3>Hope its help</h3>