The look-back time is a. the time it takes for the light from ...

[vinney12]

The look-back time is
 
  a. the time it takes for the light from an object to reach Earth.
  b. numerically equal to the distance in light-years.
  c. smaller for more distant objects.
  d. All of the other choices are correct.
  e. the time it takes for the light from an object to reach Earth and numerically equal to the distance in light-years.

Question 2

HII regions are found near stars cooler than 25,000 K because large amounts of ultraviolet photons would totally destroy the hydrogen atoms in the gas.
 
  a. True
  b. False
  Indicate whether the statement is true or false

[flexer1n1]

Answer to Question 1

e

Answer to Question 2

False

[vinney12]

Wow, this really help

[LVPMS]

Gracias!