#1

a) explain the theory of plate tectonics.

b) how does it account for the mid-atlantic ridge?

c) how does it account for volcanic island chains like hawaii?

（if answer in handwriting way, make it readble）

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle

Which of the following best describes the purpose of a nation’s boundaries? a. to limit the movement of goods and people b. to make it easier for cartographers to create maps c. to make the movement of goods and people easier d. to prevent other countries from invading territory

The poles appear to be slightly flattened in a robinson projection. question 1 options: true false