Question

She looked ____ and her eyes shone ____ an eternal light.
( use proper preposition in blanks)​

Answer 1

She looked up and her eyes shone with an eternal light.

What are prepostions in English Grammar?

• Prepostions are common english words used to show time, location and relations between different things.
  These words are placed before nouns, proper nouns, or to introduce an object.  
• In this sentence up and with are used to connect different parts of the sentence.
• Other examples of prepositions are off, in, of, by, upon from, etc.

So the correct answer will be up and with.