Answer:
The answer is <u><em>reflection</em></u>
Explanation:
the sound waves bounce off the sides of the mountain and come back to you-reflected sound waves
A Russain spacecraft was the first, not sure who though. The pilot was Yuri Gagarin
The main difference, generally speaking, is that a musical tells a story with song and dance, while a play typically sticks to spoken dialogue. This is a broad generalization; some plays feature musical content, and some musicals feature heavy amounts of spoken dialogue.
