Answer: The Europeans carried a hidden enemy to the Indians. (diseases)
Explanation: The Native people of America had no immune support for the diseases that the European explorers and well as the colonist brought to them. Diseases such as smallpox, influenza, measles, and chickenpox was very deadly to American Indians.
Herodotus - Father of History; wrote history of Persian Wars
Answer: (C) The placebo effect
Explanation:
The placebo effect is one of the type of treatment that is specifically designed for control all the therapeutic values and this effect is basically works on the various types of symptoms that is generated by our brain.
It includes the various types of procedures, inert injections and the tablets. The researcher utilized various types of placebo effect controlling system so that they can easily assess our memory.
According to the given question, the given situation is due to the placebo effect as they can easily determine the quantity of caffeine in the memory.
Therefore, Option (C) is correct.
