Answer:
The answer is B: to Amplify the sound
A Framework for K–12 Science Education: Practices, Crosscutting Concepts, and Core Ideas (Framework) recommends science education in grades K–12 be built around three major dimensions: science and engineering practices, crosscutting concepts that unify the study of science and engineering through their common application across fields, and core ideas in the major disciplines of natural science.
Answer:
calculate by urself u don't know this question
They are pre-existing rocks or pieces of once-living organisms.