definitions

3. an unpleasant or unhealthy smell or vapour
6. the romans built these to transport fresh water to highly populated areas
9. a substance that stops or slows down the growth of microorganisms
10. a heart monitor invented by William Einthoven in the early 1900s
11. protected against not affected by a disease
12. a powerful x - ray that provides a cross-section of the human body invented in 1972

1. heating liquid or food to kill microorganisms
2. the belief that substances make up the human body are: black bile, yellow bile, blood and phlegm
4. medicines that treat infections by killing bacteria
5. to give a weak form of disease to a person or animal usually by injection as a protection against the disease
7. an organism that can be seen only through a microscope examples include bacteria, protozoa, algae and fungi
8. a substance used to stimulate the production of antibodies and provide immunity against a disease