Answer:
You now this question state why a person standing at point Y hears an echo
Answer:
answer is B
Explanation:
The table below shows the wavelengths for some electromagnetic waves
I believe you are right. pH is the concentration of H+. Therefore the more acidic the more H+.
if we are walking on a perfectly smooth ground which has no friction our force would simply cancel out the force reverted by the ground and we would fall.
We need it to help push out feet off the ground
Hope those helps :)
