Plz read the passage below. earth and mars are known as terrestrial planets because they are both made up of rock and metal. however, scientists know much more about the internal structure of earth than they know about the internal structure of mars. what is the effect of the comparison signal word "both”? it signals that earth and mars have something in common. it signals that earth and mars are different from one another. it signals that scientists studied earth before studying mars. it signals that more facts about earth and mars are coming.

The correct answer is option one.

"Both" is an adverb used to indicate that the affirmation made is relevant to each alternative. In the passage, "both" means that the Earth as well as Mars share the same characteristic - each is made up of rock and metal.

After describing the similarities, the text explains the difference between the Earth and Mars, regarding scientists knowledge of the internal structure of the planets.

Answer is A

Explanation:

“way of writing” should be replaced with “writing style"

“idea” should be replaced with “purpose.”

maybe   “people from a long time ago” should be replaced with “elizabethans.”