Question

read the excerpt from chapter three of windows to the universe: revolutions in astronomy.

refracting telescopes, which use lenses to gather and focus light, need lenses made from pure, bubble-free glass. these lenses must be ground and polished with great precision. reflecting telescopes require mirrors shaped into precise parabolic curves. any mistake in shaping or polishing the lenses or mirrors could result in blurry images.

how does the author create an informative tone in this excerpt?

by sharing anecdotal stories about early telescope failures
by using persuasive language to advocate for funding new telescopes
by describing the emotions of astronomers working on telescope designs
by including technical terms and explanations about telescope construction

Explanation:

Analyze the text for technical details and tone

The excerpt discusses "refracting telescopes," "lenses," "reflecting telescopes," "mirrors," and "parabolic curves." These are technical terms related to telescope construction and optics.

Evaluate the answer choices against the text

• Option 1: There are no anecdotal stories about early failures.
• Option 2: The text does not advocate for funding.
• Option 3: No emotions of astronomers are described.
• Option 4: The author uses technical terms ("refracting telescopes," "lenses," "reflecting telescopes," "parabolic curves") and explains how they are made and function to establish an informative tone.

Answer:

• by sharing anecdotal stories about early telescope failures
• by using persuasive language to advocate for funding new telescopes
• by describing the emotions of astronomers working on telescope designs
• by including technical terms and explanations about telescope construction (Correct answer)