Gathering information and data, since it refers to the key word: <em>timeline</em>.
Answer:
Upper level
Because no one can see it but its still good and far less expensive.
Conflict means like struggle/ disagreement
Vaccinations are mainly used to prevent the spread of
a. viral diseases.
a. viral diseases.(<span>measles or <span>hepatitis B...)</span></span>
Answer:
the tendency for an impression created in one area to influence opinion in another area.
