Main Idea

Part A

What is a main idea of the passage?

• Scientists used Mariner 9 to learn about how Mars is like Earth in some ways and different in others.

• Scientists used Mariner 9 to study the atmosphere and moons of Mars and Earth.

• Scientists found that it is important to have satellites to study other planets and stars in the solar system.

• Scientists found that Mars is very different from Earth because it is far away.

   

Part B

Which parts of the passage give key details that best support the main idea in Part A?

• The headings of the sections in the text

• The first two sentences of the text

• The last two sentences of the text

• The sentences in paragraph 3

Which sentence best states a main idea of the passage?

 

• Mercury is very hot, and has no living plants or animals that are known to man.

• Earth is a planet in a solar system.

• Mercury is closer to the Sun than Earth.

• There are many unanswered questions about the planet Mercury.

Choose two details from the passage that support the answer to Part A.

• It is one of nine planets that travel around the Sun.

• It is hotter there than on any other planet.

• As far as we know, no animals can live there.

• Ponder these questions.