The coast of the State of Maine is one of the most irregular in the world. A straight line running from the southernmost coastal city to the northernmost coastal city would measure about 225 miles. If you followed the coastline between these points, you would travel more than ten times as far. This irregularity is the result of what is called a drowned coastline. The term comes from the glacial（冰川的）activity of the Ice Age. At that time, the whole area that is now Maine was part of a mountain range that towered above the sea. As the glacier descended, however, it applied enormous force on those mountains, and they sank into the sea.
As the mountains sank, ocean water charged over the lowest parts of the remaining land. And the highest parts of the former mountain range, nearest the shore, remained as islands. Marine fossils found here are 225 feet above sea level indicating the level of the shoreline prior to the glacier.
The 2,500-mile-long rocky and jagged coastline of Maine keeps watch over nearly 2,000 islands. Many of these islands are tiny and uninhabited, but many are home to blooming communities. Mt. Desert Island is one of the largest, most beautiful of the Maine coast islands left behind by the glacier. Measuring 16 miles by 12 miles, Mt. Desert was very nearly formed as two distinct islands. It is split almost in half by Somes Sound, a very deep and very narrow stretch of water seven miles long.
For years, Mt. Desert Island, particularly its major settlement, Bar Harbor, has afforded summer homes for the wealthy. Recently, though, Bar Harbor has become a new arts community as well. But the best part of the island is the unspoiled forest land known as Acadia National Park. Since the island sits on the border between two different geographical zones, the park supports the plants and animals of both zones. It also lies in a major bird migration lane and is a resting spot for many birds.
The establishment of Acadia National park in 1916 means that this natural monument will be preserved and that it will be available to all people, not just the wealthy. Visitors to Acadia may receive nature instruction from the park naturalists as well as enjoy camping, hiking, cycling, and boating. Or they may choose to spend time at the museum learning about the Stone Age inhabitants of the island.
72．The large number of small islands along the coast of Maine is the result of __________.
A. the drowning of the Maine coastline
B. glacier’s forcing mountains into the sea
C. the irregularity of the Maine coastline
D. ocean water’s flooding the mountain range
73．From the passage, we learn that __________.
A. the coastline of Maine is ten times longer after the Ice Age
B. there are more than 2500 islands along the Maine coastline
C. Mt. Desert Island has been broken apart by a 7-mile-long water stretch
D. an arts community gave way to the summer homes on Mt. Desert Island
74．What CANNOT be inferred about the Acadia Nation Park?
A. It welcomes all the people, rich or poor.
B. It has much appeal for bird-watching lovers.
C. It offers visitors both entertainment and education.
D. It is a border between the two geographical zones.
75．Which of the following might be the best title of the passage?
A. The past and the present of Maine B. The formation of Maine coastline
C. Efforts for preserving national parks D. Tourist attractions on Mt. Desert Island