How do we know what goes on under the surface of the Sun?
a. We have X-ray images from satellites of the interior of the Sun.
b. Astronomers create mathematical models that use the laws of physics, the Sun's observed composition and mass, and computers to predict internal conditions.
c. We have sent probes below the surface of the Sun.
d. By measuring Doppler shifts, we observe vibrations of the Sun's surface that are created deep within the Sun.

b. Astronomers create mathematical models that use the laws of physics, the Sun's observed composition and mass, and computers to predict internal conditions.

d. By measuring Doppler shifts, we observe vibrations of the Sun's surface that are created deep within the Sun.

Explanation:

We know what goes on under the surface of the Sun by doing the followings;

i. By measuring Doppler shifts, we observe vibrations of the Sun's surface that are created deep within the Sun.

ii. Astronomers create mathematical models that use the laws of physics, the Sun's observed composition and mass, and computers to predict internal conditions.

total distance/total time

(85 + 82)/(5+3)

167/8

20 just over