The correct answer is seismic waves.
A sudden movement of the Earth's crust followed by the production of seismic waves is known as an earthquake. The seismic waves travel outwards from the source. The sudden vibration or ground motion is generated due to a brisk discharge of accumulated energy.
The vibrations, which travel via Earth carrying the energy discharged at the time of an earthquake is known as seismic waves. The earthquakes are usually determined with a help of seismometer, called seismograph.
I think the correct answer from the choices listed above is the third option. The barrel of a gun is also known as bore. The barrel is the metal tube which the bullet is fired and the bore is the inside of the barrel. It is the one closest to the barrel so it must be the answer.
Permian-Triassic extinction
RNA polymerase (green) synthesizes RNA by following a strand of DNA. RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription.
