Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
The distance covered will be:

The correct answer is
D).
Boiling water is a physical change, because it is changing state of matter, there is a controllable temperature change, and you can change it back.
Frying the egg white is a chemical change, because there is a change of matter, controllable temperature change, but you CAN'T change it back.
Answer:
1. bitter
2. turns litmus paper red
3. oxygen, hydrogen, and molecules.
Explanation:
I believe that the answer is 11.5