Is the Hubble constant really constant? What will be an ideal ...

Is the Hubble constant really constant?
 
  What will be an ideal response?

Question 2

Emission nebulae like M42 occur only near stars that emit large amounts of
 
  A) infrared heat.
  B) X-rays and gamma rays.
  C) microwaves.
  D) ultraviolet radiation.
  E) visible light.

Question 3

The spectra of interstellar gas clouds show that they have the same basic composition as
 
  A) Earth's atmosphere.
  B) stars.
  C) asteroids.
  D) interstellar dust.
  E) the Martian polar caps.

Question 4

The planet whose pole was facing the Sun when Voyager 2 approached in 1986 was
 
  A) Uranus. B) Neptune. C) Saturn. D) Jupiter. E) Mars.