There are two basic types of glaciers, those that flow outward in all directions with

            little regard for any underlying terrain and those that are confined by terrain to a

            particular path.

 Line        The first category of glaciers includes those massive blankets that cover whole

  (5)      continents, appropriately called ice sheets. There must be over 50,000 square kilometers

            of land covered with ice for the glacier to qualify as an ice sheet. When portions of an

            ice sheet spread out over the ocean, they form ice shelves.

               About 20,000 years ago the Cordilleran Ice Sheet covered nearly all the mountains 

            in southern Alaska, western Canada, and the western United States. It was about

 (10)      3 kilometers deep at its thickest point in northern Alberta. Now there are only two

            sheets left on Earth, those covering Greenland and Antarctica.

               Any domelike body of ice that also flows out in all directions but covers less than

            50,000 square kilometers is called an ice cap. Although ice caps are rare nowadays,

            there are a number in northeastern Canada, on Baffin Island, and on the Queen

 (15)      Elizabeth Islands.

               The second category of glaciers includes those of a variety of shapes and sizes

            generally called mountain or alpine glaciers. Mountain glaciers are typically identified

            by the landform that controls their flow. One form of mountain glacier that resembles

            an ice cap in that it flows outward in several directions is called an ice field. The

 (20)      difference between an ice field and an ice cap is subtle. Essentially, the flow of an ice

            field is somewhat controlled by surrounding terrain and thus does not have the domelike

            shape of a cap. There are several ice fields in the Wrangell, St. Elias, and Chugach

            mountains of Alaska and northern British Columbia.

                Less spectacular than large ice fields are the most common types of mountain

 (25)      glaciers : the cirque and valley glaciers. Cirque glaciers are found in depressions in the

            surface of the land and have a characteristic circular shape. The ice of valley glaciers,

            bound by terrain, flows down valleys, curves around their corners, and falls over cliffs.

            9. What does the passage mainly discuss?

              (A) Where major glaciers are located

              (B) How glaciers shape the land

              (C) How glaciers are formed

              (D) The different kinds of glaciers

            10. It can be inferred that ice sheets are so named for which of the

                following reasons?

              (A) They are confined to mountain valleys.

              (B) They cover large areas of land.

              (C) They are thicker in some areas than in others.

              (D) They have a characteristic circular shape.

            11. According to the passage, where was the Cordilleran Ice Sheet thickest ?

              (A) Alaska

              (B) Greenland

              (C) Alberta

              (D) Antarctica

            12. The word “rare” in line 13 is closest in meaning to

              (A) small

              (B) unusual

              (C) valuable

              (D) widespread

            13. According to the passage (paragraph 5), ice fields resemble ice caps in

                which of the following ways?

              (A) Their shape

              (B) Their flow

              (C) Their texture

              (D) Their location

            14. All of the following are alpine glaciers EXCEPT

              (A) cirque glaciers

              (B) ice caps

              (C) valley glaciers

              (D) ice fields

            15. The word “depressions” in line 25 is closest in meaning to

              (A) intrusion

              (B) dejection

              (C) concaves

              (D) convexes

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