Answer:
The word "protracted" means lasting longer than expected, or unusually long, so what protracted most clearly means based on the context of the excerpt is how the time period of celestial motion studies must have lasted unusually long.
Circle a, b or c.
1. I <u>travel</u> abroad five or six times a year.
2. I had a terrible <u>trip</u> here - the flight was delayed, and then we had a lot of turbulence.
3. Is Hannah back from her <u>trip</u> to South America?
4. We have to <u>travel</u> 400 km if we want to see my grandparents.
5. My sister wants to go on a <u>journey</u> around the world in her gap year.
6. My <u>trip</u> to work takes me about an hour.
Hope this helps!
-<em>heyo</em>
A non-restrictive modifier add information that does not restrict who the subject can refer to (compare to "The one Marlena that enjoys many subjects" -this one restricts the subject to a specific Marlena). Here it's "who enjoys many different subjects" - it adds additional information about her, but doesn't change the referent.
A stake is a piece of wood or other material, usually long and slender, pointed at one end so as to be easily driven into the ground as a marker or a support while reward is something of value given in return for an act.
Hope this helps
