Answer:
12
Explanation:
Suppose the four different strains are P, Q, R, S. Thus, the first infection can be from any of the four strains and it occurs in 4 ways.
Since an individual cannot be infected again with the strain from which he/she is been previously infected;
Then, at the second time;
The possible number of strain to be infected with = 4-1 = 3 ways
Thus; the number of possible different levels of severity can be viewed by forming two lettered word P, Q, R, and S without repetition which is:
= 4 × 3
= 12
Answer:
The waiting room became the conditioned stimulus.
Explanation:
Conditioned stimulus is the reflexive behaviors or the learned behavior.
This stimulus may be defined as a neutral stimulus that with some time and some training will evoke a response by continuously being associated with any other natural occurring stimulus.
Answer:
troposphere like and comment
The process by which gases hold heat in the air. The greenhouse effect is a natural process that keeps Earth's<span> atmosphere at a temperature that is comfortable for</span>most<span> living things. What </span>absorbs most of the energy that is radiated from Earth's surface<span>? water vapor, carbon dioxide, methane, and other gases.</span>
