Which of the following is true of the origin of life on Earth?
A) Evidence suggests that the earliest living things contained hard bones and shells.
B) The oldest living fossils indicate that life began on land.
C) Evidence suggests that the earliest living things were multicellular and gigantic.
D) The oldest fossils indicate that life began in the sea.
Question 2
The _____ is the interval of the radio spectrum between the 21-cm hydrogen emission line and the 18-cm OH emission line; these are likely wavelengths to use in the search for extraterrestrial life.
A) water hole
B) habitable zone
C) Arecibo beacon
D) DNS zone