Question

select the word that means an idea believed to be true. around 1514, astronomer nicolaus copernicus questioned the doctrine that earth occupied the center of the universe. in 1543, he published a book explaining his observations and calculations. most people discounted copernicus’s book until many years later, when scientists affirmed that the planets do orbit the sun. submit

Explanation:

We need to find a word in the passage that means "an idea believed to be true". Looking at the passage, the word "doctrine" is used to refer to the idea that Earth occupied the center of the universe (an idea that was believed to be true at that time, even though Copernicus questioned it). Other words like "observations", "calculations", "affirmed" don't fit the definition. "Doctrine" means a set of beliefs or ideas that are held to be true, especially in a religious or philosophical context, but here it's used in a scientific context about a widely - held belief.

Answer:

doctrine