Answer:
Astronomy is one of the oldest sciences
She should start consuming 2,600 calories a day. That way after she burns off her 600 calories, she is still only consuming and storing 2,000 calories.
"Has" would make more sense. A tip would be to read the sentence with both words, one word at a time obviously (So Everyone HAS already voted in the election.) and just go with your gut on which one makes more sense, you can do it!
if you sent me pics of the story i would be able to answer it
