How are glacial troughs formed? (need as soon as possible)

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.

The world wars of the twentieth century immediately led to a. the establishment of a communist bloc in eastern europe b. the urbanization of europe’s societies c. an emphasis on humanism d. an emphasis on ties to greek and roman societies select the best answer from the choices provided. a b c d

Sink holes may eventually for to join a. wide valleys b. zone of aeration c. dripstones d. aquifer