43. The word "symmetrical" in line 9 is closest in meaning to (A) proportionally balanced (B) commonly seen (C) typically large (D) steadily growing

49. Why does the author mention the Virgo galaxy and the Andromeda galaxy in the third paragraph? (A) To describe the effect that distance has no visibility. (B) To compare the ages of two relatively young galaxies. (C) To emphasize the vast distances of the galaxies from Earth. (D) To explain why certain galaxies cannot be seen by a telescope.