Topic & Main Idea HW Answers

These are possible answers for Exercise 8 (p. 175) (Topic/Main Idea HW)

1. Paragraph 1
Topic: Reason for changes in the earth's shape
Main Idea: There are many different causes for changes in the earth's shape. OR The shape of the earth is always changing and these changes have many different causes.

2. Paragraph 2
Topic: The similarities between Mt. Vesuvius and Mt. Pinatubo
Main Idea: There are many similarities between Mt. Vesuvius and Mt. Pinatubo, even though they are not nearby. OR Mt. Vesuvius in Italy and Mt. Pinatubo in the Philippines are both famous volcanoes, and they are similar in many ways.

3. Paragraph 3
Topic: The things that scientists learn and understand/know about the earth.
Main Idea: Scientists have things they learn and understand/know about the Earth, but they don't know about all of its systems yet.