Compared to optical telescopes, radio telescopes are built large ...

[Anajune7]

Compared to optical telescopes, radio telescopes are built large because
 
  A) radio waves have very long wavelengths.
  B) radio waves are absorbed by the atmosphere.
  C) atmospheric turbulence is more of a problem.
  D) they're less expensive to make than optical telescopes.
  E) radio sources are harder to find.

Question 2

Which three worlds have almost identical densities?
 
  A) Mercury, Mars, and our Moon
  B) Mercury, Venus, and Earth
  C) Earth, Moon, and Mars
  D) Mercury, Earth, and Mars
  E) Deimos, Phobos, and our Moon

[Shshxj]

Answer to Question 1

A

Answer to Question 2

B

[Anajune7]

Thank you!

[Shshxj]

Always glad to help...