19)
What is the purpose of this article?
A) to inform
B) to convince
C) to persuade
D) to entertain
20)
Which statement BEST reflects the author's purpose in writing this passage?
A) The author's purpose is to inform the reader about how a new Pacific island was formed.
B) The author's purpose is to entertain readers by making them laugh at life on a new Pacific island.
C) The author's purpose is to entertain the reader by discussing possible uses for a new Pacific island.
D) The author's purpose is to describe the various plants and animals that can be found on a new Pacific island.
1NORTHERN PACIFIC OCEAN—Scientists have discovered a new, currently unnamed island in the northern Pacific Ocean. The small island is located in an isolated area between Hawaii and the Marshall Islands. Scientists believe that an erupting volcano formed the island. The new land mass measures roughly two square miles and rises nearly ten feet above sea level. 

2Islands form when magma inside the earth spills onto the earth’s surface. Once magma hits the planet’s surface, it is called lava. The erupted lava then cools and hardens to form rocks and land. Scientists believe the volcano that created this new island has been erupting under the ocean for hundreds of years. Nevertheless, the lava has only recently risen above the water’s surface to form land. Scientists think the new island will expand as the volcano continues to erupt.

3The theory of plate movement informs scientists’ knowledge of volcanoes. Scientists believe the earth’s crust consists of eight major, as well as dozens of minor, pieces of land called plates. These plates float on a sea of magma that flows under the earth’s surface. The plates’ movements cause continents to shift and mountains to form. They are also responsible for earthquakes and volcanic eruptions. 

4Volcanoes can form in three ways. Some volcanoes form when the earth’s plates separate and pull apart from each other. The movement allows magma to bubble up in the gap between the plates. The Mid-Atlantic Ridge under the Atlantic Ocean is formed by separating plates. Although few people know about, it is actually the earth’s longest mountain chain. 

5Volcanoes can also occur when one plate is forced underneath another. The lower plate melts into magma, which later erupts from the earth as lava. The volcanoes in a part of the Pacific Ocean known as the Ring of Fire were formed in this way. 

6The final way that volcanoes can occur is when hot spots of magma burn through thin parts of the earth’s crust. Hot spots formed the Hawaiian Islands and the new unnamed Pacific island. The lava released from hot spot volcanoes typically flows slowly from the volcano’s cone.

7Scientists plan to continue studying the new volcanic island in the hope of learning more about the forces that shape the earth and its land masses.