According to the Doppler effect, the sound of a police car siren is louder and high pitched as it approaches the observer.
The answer to this question is the term Gross Anatomy. The Gross Anatomy is also known as topographical anatomy which is the study of large body structures at the macroscopic levels. Gross anatomy deals with body structures that with minimal magnification because it is seen by the naked eye.
Answer:
Because you body is introduced to the virus, it is familiar to it and can build up an immunity to the weakened form so when the actual virus invades, your body know what to do.
Explanation:
