Question

I want to shorten the paragraph of Primary.
Can anyone help me with it?​

Answer 1

Answer:

Primary waves are the first one to reach the surface of the earth after the energy is emitted in the earth's interior. They travel at a very high speed. The wave moves to and fro, therefore these waves are also called forward backward waves waves. But while travelling through liquid medium their direction gets changed. It is because of the primary waves that the buildings on the earth's surface move back and forth.