Which one of the methods below enables astronomers to measure the ...

[sdfghj]

Which one of the methods below enables astronomers to measure the distance of a star near the Sun in our galaxy?
 
  a. sound echoes knowing the speed of sound and time
  b. parallax using Earth's orbit
  c. human binocular vision
  d. Balmer series
  e. none of the above

Question 2

The ___________ of a black hole is the radius from a black hole at which the escape velocity is approximately equal to the speed of light.
 
  a. Roche limit
  b. Lagrangian point
  c. Chandraskhar limit
  d. Hubble radius
  e. event horizon

[smrtceo]

Answer to Question 1

b

Answer to Question 2

e

[sdfghj]

YES! Correct, THANKS for helping me on my review

[Dnite]

Thanks for the timely response, appreciate it