Match the items on the right to the items on the left.

Fluoridation	??? Micro-organisms that need to take over cells to reproduce. Disinfecting water Tiny micro-organisms that can live outside cells Small single-celled animals Adding sodium fluoride to drinking water.
Protozoa	??? Micro-organisms that need to take over cells to reproduce. Disinfecting water Tiny micro-organisms that can live outside cells Small single-celled animals Adding sodium fluoride to drinking water.
Bacteria	??? Micro-organisms that need to take over cells to reproduce. Disinfecting water Tiny micro-organisms that can live outside cells Small single-celled animals Adding sodium fluoride to drinking water.
Viruses	??? Micro-organisms that need to take over cells to reproduce. Disinfecting water Tiny micro-organisms that can live outside cells Small single-celled animals Adding sodium fluoride to drinking water.
Chlorination	??? Micro-organisms that need to take over cells to reproduce. Disinfecting water Tiny micro-organisms that can live outside cells Small single-celled animals Adding sodium fluoride to drinking water.