<span>The right answer is D. In a situation where the sound wave reaches the ear and the reflected wave reaches the ear less than 0.1 seconds later, the individual would not be able to hear an echo. There needs to a far more significant delay between the sound and the reflection of said sound reaching the listener's ear for the echo effect to become apparent.</span>
And the significant amount of volume can be differed by its solitude
The charge of a proton is positive.
B. The energy barrier between reactants and products
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