What is the source of an earthquake called?

If you could drill a hole straight to the center of the earth, and keep track of what the hole is going through, youwould find: a) you would go through one sort of material, and then a different, denser material, and then a still-different, still-denser material, because the planet is made of concentric layers, sort of like an onion. b) you would go through one sort of material all the way to the center, because the planet is all mixed up. c) if your hole started at the north pole, you would go through different layers of different materials, but ifyour hole started at the equator, you would go through one sort of material all the way to the center. d) if your hole started at the equator, you would go through different layers of different materials, but if yourhole started at the north pole, you would go through one sort of material all the way to the center. e) you would strike diet pepsi when you got to the center.

Since 1980, which three countries have either attacked or been attacked by iraq? a. iran, turkey, united states b. iran, israel, jordan c. iran, kuwait, united states d. iran, saudi arabia, egypt

Which of these scenarios is most similar to the aztec empire's system of agriculture? a. a farmer plants the same crops b. a farmer observes the behavior c. a farmer watches the sun’s patterns d. a farmer plants many different crops