Answer:

Explanation:
The speed of the sound wave is:


The frequency is:



Answer:
The results only apply to the individual or group being studied.
Explanation:
Case study is one of the methods followed for researches and observations. It helps in an advanced and detailed method of getting along with a particular topic. In case studies, the topic or the subject is studied extensively and observations are made through them. Case studies involve a detailed study of individual or group whose results are not in a general form. The results are applied to the specific individual or the group.
The following are the answers:
12. I once asked Red Cloud if he could recall having ever been afraid, and in reply he told me this story. He was about sixteen years old and had already been once or twice upon the warpath, when one fall his people were hunting in the Big Horn country, where they might expect trouble at any moment with the hostile Crows or Shoshones.
13. Red Cloud had followed a single buffalo bull into the Bad Lands and was out of sight and hearing of his companions. When he had brought down his game, he noted carefully every feature of his surroundings so that he might at once detect anything unusual, and tied his horse with a long lariat to the horn of the dead bison, while skinning and cutting up the meat so as to pack it to camp.
14. Every few minutes he paused in his work to scrutinize the landscape, for he had a feeling that danger was not far off.
Answer:
During adolescence
Explanation:
A peer group is a group of people who have similar interests, age, background, or social status. Peer groups influence a person during their entire life, but their impact is the most important during adolescence. Adolescents tend to spend less time with their parents, whose influence is the greatest during childhood, and spend more time with their peers. This is especially noticeable in the case of those who are not close or have many conflicts with their parents. Such individuals seek support elsewhere, usually turning to their peers. Most adolescents in this situation do not carefully choose what kind of group they join. If they are accepted, it does not matter if the group's influence is good or bad. Gangs are a common example of a peer group characterized by negative or even illegal activities.
Answer:
I think its A.
Explanation:
I think it's A, but music ain't my strong point.