阅读理解。
Everglades National Park is the most endangered national park in America. The purpose of making a
national park is to protect the plants and animals that live there. But things that happen outside the park
also affect the life within it.
Everglades National Park is part of a much larger area known as the Everglades. At one time, water
flowed freely in the Everglades. During the rainy season, water would fill the Kissimmee River. Then it
flowed into Lake Okeechobee. Once the lake became full, water spilled over onto the flatland. From there
a shallow sheet of water moved slowly down the Florida Peninsula. Then it emptied into Florida Bay. This
shallow sheet of water was the Everglades River. It was only a few inches deep. But it was up t0 50 miles
wide and over 100 miles long.
The Everglades is home to many plants and animals found nowhere else in the world. Today, some of
these plants and animals are in danger of disappearing forever.
The main reason is that the Everglades is no longer a free-flowing river. Canals have been built to drain
(排干) most of the shallow river. People have also built a dam to hold back water from Lake Okeechobee.
Most of the water from the Everglades is trapped in man-made lakes. Cutting off the flow of water into
Everglades National Park has done more harm than good. Now it threatens the wildlife in the park.
Water pollution is another reason some plants and animals are disappearing. Years ago, large areas of the
Everglades were drained and turned into farmland. Today the fertilizers (肥料) used on crops are polluting
the water. The "river of grass" is slowly disappearing. Many kinds of plants are disappearing. Animals that
depend on these plants for food no longer have anything to eat.
The problems facing Everglades National Park are very serious. But there is still hope. Work is already
under way to save the Everglades. The federal government, the state of Florida, and several other groups
are all working together to try to undo the damage.
1. Why was a national park built in America?
A. To protect people.
B. To protect the plants and animals.
C. To provide a fun place for people.
D. To keep animals from going in the park.
2. The second paragraph mainly tells us _____.
A. how water flowed into the Everglades River
B. how big Everglades River was
C. what the Everglades used to be like
D. what happened to Everglades River during the rainy season
3. The main reason for the animals being endangered is that _____.
A. there's no rain there now
B. people cut the plants that the animals feed on
C. large areas of Everglades were turned into buildings
D. the water flowing into the Everglades has been cut off
4. From the end of the passage, we know that _____.
A. nobody takes care of the Everglades
B. some measures are being taken to protect the environment of Everglades
C. the environment of Everglades will be worse and worse
D. the government is worried about Everglades but has no way
平衡最有效的方法是（）