In which seismogram is the time probe placed at the beginning of the p waves?

seismogram a
seismogram b
seismogram c
seismogram d

Answer;

Seismogram C

Explanation;

In Seismogram C the time probe is placed at the beginning of the P waves because the C line doesn't  start till u see the signal wave.

A seismogram is a graph output or a record written by a seismograph in response to ground motions produced by an earthquake, explosion, or other ground-motion sources.. It is a record of the ground motion at a measuring station as a function of time.

i would think it's food chain

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.