Many students are planning field trips as spring draws near. Fourteen-year-old Zhou Liqun is busy digging holes along rivers. The girl and her "One Piece of Paper Team" are planting trees to improve the environment.  They collect waste paper to sell for trees and have set up websites to spread the message of connections between humans and nature. "We want to make environmental protection everyone's habit," says the girl. "Even a piece of paper matters."  Eager to join Zhou in such meaningful work? Now you are offered advice on what to do. Last month, measures for public participation in environmental protection were published by the State Environmental protection Administration  . The special measures are expected to change the light rain of the past into a storm of environmental protection.  Last year's Songhua River pollution acted as an alarm to Chinese people. According to SEPA officials, environmental pollution has become serious, and will continue so for the next 15 years.   A recent survey showed that though most Chinese people care about environmental problems, they don't put their concerns into practice. One reason is that they don't know how. So the newly published measures present information about how to report environmental problems and how to join in the battle against pollution.  Actually there is much you can do in daily life. Buy less to reduce waste. Don't throw away things before you have made the most use of them. Use electricity, water and gas only when necessary. Switch them off when you don't need them.  Everyone can participate in making the planet suitable for future generations. Why not join in and make our world more fantastic? What is the writer's purpose of writing the passage?
To praise Zhou Liqun and her friends. To remind us that our world is heavily polluted. To give us advice on how to make environmental protection everyone's habit. To call on people to join in the fight against the environmental pollution.
Question: Many students are planning field trips as spring draws near. Fourteen-year-old Zhou Liqun is busy digging holes along rivers. The girl and her "One Piece of Paper Team" are planting trees to improve the environment.  They collect waste paper to sell for trees and have set up websites to spread the message of connections between humans and nature. "We want to make environmental protection everyone's habit," says the girl. "Even a piece of paper matters."  Eager to join Zhou in such meaningful work? Now you are offered advice on what to do. Last month, measures for public participation in environmental protection were published by the State Environmental protection Administration  . The special measures are expected to change the light rain of the past into a storm of environmental protection.  Last year's Songhua River pollution acted as an alarm to Chinese people. According to SEPA officials, environmental pollution has become serious, and will continue so for the next 15 years.   A recent survey showed that though most Chinese people care about environmental problems, they don't put their concerns into practice. One reason is that they don't know how. So the newly published measures present information about how to report environmental problems and how to join in the battle against pollution.  Actually there is much you can do in daily life. Buy less to reduce waste. Don't throw away things before you have made the most use of them. Use electricity, water and gas only when necessary. Switch them off when you don't need them.  Everyone can participate in making the planet suitable for future generations. Why not join in and make our world more fantastic? What is the writer's purpose of writing the passage?
A. To praise Zhou Liqun and her friends.
B. To remind us that our world is heavily polluted.
C. To give us advice on how to make environmental protection everyone's habit.
D. To call on people to join in the fight against the environmental pollution.
Answer: