Meteorites are important because A) some come from the Moon ...

[audragclark]

Meteorites are important because
 
  A) some come from the Moon and Mars, as well as the asteroid belt.
  B) they contain pristine material from the solar nebula.
  C) large ones may cause mass extinctions.
  D) All of the above are true.
  E) None of the above is true.

Question 2

From an observational standpoint, what is a pulsar?
 
  A) an object that emits flashes of light several times per second (or even faster), with near perfect regularity
  B) a star that slowly changes its brightness, getting dimmer and then brighter, with a period of anywhere from a few hours to a few weeks
  C) an object that emits random pulses of light, sometimes with only a fraction of a second between pulses and other times with several days between pulses
  D) a star that changes color rapidly, from blue to red and back again

[vboyd24]

Answer to Question 1

D

Answer to Question 2

A

[audragclark]

TYSM

[duy1981999]

Gracias!