During the eighteenth and nineteenth centuries, attempts to ...

[serike]

During the eighteenth and nineteenth centuries, attempts to precisely measure the astronomical unit relied largely on rare
 
  A) total solar eclipses.
  B) transits of the inferior planets across the Sun.
  C) passages of comets close to the Earth.
  D) maximum elongations of Venus.
  E) oppositions of Mars.

Question 2

Most interstellar clouds remain stable in size because the force of gravity is opposed by ________ within the cloud.
 
  A) degeneracy pressure
  B) radiation pressure
  C) stellar winds
  D) thermal pressure

[mcomstock09]

Answer to Question 1

B

Answer to Question 2

D

[serike]

Both answers were spot on, thank you once again

[mcomstock09]

Great! Please up vote