Once you understand this, its pretty simple. 50 hertz= 50 vibrations. 100 hertz=100 vibration. So to answer your question 200 hertz=200 vibrations. Your answer is C.
They are all rock with different size and shapes and are located in different areas possibly in the same areas but they all have there own unique textures from the photographs and 3 of them look like maybe a fossil of some type of when the dinosaurs where still around and the rocks on the top left corner look smooth and are a small type of igneous rocks. That have been soothed over the years.
Answer:
B-By studying the different ways that people react to emotional
Explanation:
Sociologists will study by observation.
