Soils rich in humus improve plant growth. Earthworms breakdown organic matter to form humus. From the data, it can be seen that plant growth is high in soil that has humus.
<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>
