This sentence is from the passage. "Radio telescopes have helped astronomers make many
exciting discoveries about space." (Paragraph 10)
Which detail from the passage best supports this idea?
O 1. "Throughout history, people have studied the
stars." (Paragraph 1)
O 2. "When scientists want to study stars' radio
waves, they use a radio telescope."
(Paragraph 3)
3. "Radio telescopes' dishes are easier to build in
large sizes than the mirrors needed for optical
telescopes." (Paragraph 8)
4. "Scientists are using radio telescopes in many
ways, such as to learn about how stars form."
(Paragraph 11)