1. Most caves are due to

A) gas bubbles in volcanic deposits.
B) rapid cooling of molten rock.
C) the solvent action of groundwater.
D) erosion by running water.

2. A stream's ability to transport debris depends on all of the following except the

A) stream's slope.
B) volume of water that flows.
C) amount and kind of debris.
D) water temperature.

3. Rain is most abundant in the

A) prevailing westerlies of the middle latitudes.
B) horse latitudes between the middle latitudes and the trade wind belts.
C) trade wind belts.
D) doldrums of the equatorial regions.

4. Water covers

A) less than half the earth's surface.
B) roughly half the earth's surface.
C) more than half the earth's surface.
D) Any of these choices could be correct, depending on the season.

5. The tendency of certain minerals to split along particular planes is called

A) foliation.
B) faulting.
C) cleavage.
D) gneiss.

6. Relative to the average depth of the oceans below sea level, the average height of the continents above sea level is

A) greater.
B) smaller.
C) about the same.
D) greater at low tide, smaller at high tide.

7. Igneous rocks have been formed by

A) cooling from a molten state.
B) precipitation from solution.
C) the alteration of other rocks by heat.
D) the alteration of other rocks by pressure.

8. Tornadoes

A) are narrow cyclonic storms.
B) are narrow anticyclonic storms.
C) are at the central parts of hurricanes.
D) occur mainly in the winter.

9. Tsunamis

A) are extremely rare.
B) occur mainly in the Atlantic Ocean.
C) are caused by undersea earthquakes.
D) are caused by hurricanes.

10. The earth's crust

A) has an approximately constant thickness of about 100 m.
B) has an approximately constant thickness of about 5 km.
C) has an approximately constant thickness of about 35 km.
D) varies in thickness from about 5 km under the oceans to about 35 km under the continents.

11. Most of the world's freshwater is found

A) in lakes and rivers.
B) in clouds.
C) frozen in Greenland.
D) frozen in Antarctica.

12. Among the reasons why the earth's core is believed to consist mainly of molten iron is (are)

A) the density of iron.
B) the electrical conductivity of iron.
C) the relative abundance of iron in the universe.
D) that earthquake S waves do not pass through the core.
E) All of the above

13. Rivers produce which one or more of the following?

A) alluvial fans
B) till
C) deltas
D) water tables
E) Both A and C

14. Earthquakes are least likely to occur

A) in California.
B) along the west coast of South America.
C) in Japan.
D) in Russia.

15. Temperatures in the stratosphere increase with altitude because of the presence there of

A) water vapor.
B) ozone.
C) pollutants.
D) CFCs.

16. A rock that does not consist chiefly of calcite is

A) limestone.
B) chert.
C) chalk.
D) marble.

17. Of the following rocks, the least resistant to chemical weathering is

A) limestone.
B) slate.
C) chert.
D) quartzite.

18. On a summer night, coastal land cools below the temperature of the nearby sea. The result is a "land breeze" that blows

A) onshore.
B) offshore.
C) parallel to the shore.
D) Any of these choices could be correct, depending on the region.

19. An isobar is

A) a line of constant pressure on a weather map.
B) a line of constant temperature on a weather map.
C) a unit of atmospheric pressure.
D) the path followed by a wind.

20. On a worldwide basis, glaciers carve landscapes

A) to a smaller extent than streams.
B) to about the same extent as streams.
C) to a greater extent than streams.
D) only during the ice ages.