A) When the risk is low, the return is high
Answer:
A double-blind study is one in which neither the participants nor the experimenters know who is receiving a particular treatment. This procedure is utilized to prevent bias in research results. Double-blind studies are particularly useful for preventing bias due to demand characteristics or the placebo effect.
For example, let's imagine that researchers are investigating the effects of a new drug. In a double-blind study, the researchers who interact with the participants would not know who was receiving the actual drug and who was receiving a placebo.
Answer:
Rivers.
Explanation:
Most of Africa is covered with deserts and savannahs which are difficult to live in but rivers around the continent helped make sure cities and civilizations flourished.
Number 18 is F btw. Your welcome.
