Author Question: Evidence for very recent water erosion on Mars comes from the observations of A) dark streaks on ... (Read 60 times)

future617RT · **on:** Jul 27, 2018

Evidence for very recent water erosion on Mars comes from the observations of

A) dark streaks on crater walls
B) channels carved on the slopes of volcanoes
C) dried up river beds on the highlands
D) mud flows surrounding craters

Question 2

Before the decoupling

A) the Universe was transparent to radiation.
B) the Universe was opaque to radiation.
C) protons and electrons combined to form atoms.
D) there was more helium than hydrogen.
E) deuterium produced electrons and positrons.