If you were trying to build a soundproof room, which of the following materials would you choose in order to absorb the most sound, based on the coefficient of absorption for each material? a. heavy curtains b. wood c. concrete d. carpet

Explanation :  

Absorption coefficient of a material determines how much sound is absorbed by the material.

To build a soundproof room, Heavy curtains and carpet can be used. They reduce reverberation.

Reverberation means an echoing sound which persists for some time. For example, when we bang on a huge piece of metal, we hear the reverberation even after we stop banging.  

Hence, option (A) and (D) are correct.

an ion is a charged atom or molecule. it is charged because the number of electrons do not equal the number of protons in the atom or molecule. an atom can acquire a positive charge or a negative charge depending on whether the number of electrons in an atom is greater or less then the number of protons in the atom.

answer: i think he can see forward ten seconds and move forward ten seconds but giorno can undo his actions with ger.

explanation: