Answer:
By looking at the amount of time between the P and S wave on a seismographs recorded on a seismograph, scientists can tell how far away the earthquake was from that location. However, they can't tell in what direction from the seismograph the earthquake was, only how far away it was.
Explanation:
B. Most rocks are composed of single mineral
Answer:
If the question is which can make a buffer, then NH3, NH4Cl should be correct. Because Ammonium (NH4) is conjugate acid of NH3 so they can form an equilibrium which is basically a buffer whose purpose is to resist pH change.
Explanation: