Which causes sand dunes to form

a. ocean waves

b. weathering from old rocks in the dessert

c. gravity?

A certain population of beavers builds dams across a stream to catch fish. Some years the stream carries more water than other years. The data below was collected by scientists studying the stream over four years.

Relate the crusades to exploration in the east.

Although it is highly unlikely to happen, suppose that we suddenly discovered that all these years we'd been wrong about the distance from Earth to the Sun, and it is actually 10% greater than we'd thought.

What so shamals and simooms have in common?

Identify four of Jerusalem's holy sites. To which religion is each site sacred, and why is it considered important?

How would Global temperatures change if the earth had substantially more land area and less ocean area than it does at the present? How would such changes influence the biosphere?

5. (1) (Fill in the blank) The composition of the core includes mostly what metal

Why do people immigrate to Western Europe? A. Western Europe's command economy insurance people will have jobs B. The climate in western Europe is enjoyable C. Western Europe offers an escape from political oppression D.

Water that contains very little dissolved salts is called 1. freshwater 2. saline water 3. mixed water 4. impure water

Explain why scientists might use models to represent Earth's processes.