Answer:
3 should be right im sure i might be right leave a review if wrong and how it was have a nice day
Explanation:
<span>Silicon dioxide
forms the cell walls of diatoms. These diatoms are a group of algae.
Phytoplanktons are the most common types of diatoms that are unicellular. These
organisms can form colonies in the shapes of filaments or ribbons, fans,
zigzags, and stars that are perfect for monitoring environmental conditions,
particularly water quality in the past and present. </span>
The immune system<span> is made up of a network of cells, tissues, and organs that work together to protect the body. One of the important cells involved are white blood cells, also called leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances.</span>
<span>The upstairs of a house being warmer than the downstairs is an example of heat transfer by -- convection</span>
