Read the passage carefully, and answer the questions that follow it.
Our planet is at risk. Our environment is under threat. The air we breathe, the water we drink, the seas we fish in, and soils we farm, the forests, animals and plants which surround us are in danger. New terms and words describe these problems - acid rain, the greenhouse effect, global warming, holes in the ozone layer, desertification and industrial pollution.
We are changing our environment. More and more gases and wastes escape from our factories. Rubbish, oil spillages and detergents damage our rivers and seas. Forests give us timber and paper, but their loss results in soil erosion and also endangers wildlife.
The richer countries of the world are mainly responsible for industrial pollution. This is where most of all the commercial energy is produced. In developing countries, poverty cause people to change their environment to overgraze grassland, to cut down trees for new land and firewood, to farm poor soil for food.
The United Nations Environmental Protection Agency says that an area of forest the size of Sierra Leone disappears every year. Trees are cut down for timber which is used for building, furniture, paper and fuel. They are also destroyed to provide land on which to graze animals and build new villages and towns. But trees have many other important uses. Trees protect the land from heavy downpour of ram and their roots help to hold the soil together. Forests are also the home of many living things. The Amazon forest contains one fifth of all the species of birds in the world.
In our forests, there may be plants and animals which could help in the discovery of new medicines of crops. To rescue and conserve our beautiful world, we must act cooperatively. Individuals, communities, nations and international associations, all have a responsibility. By learning to protect the natural environment, we can manage the earth's resources for generations to come.
The message of the writer is the ____________
A. need for the developed countries to assist the poorer ones B. grave dangers of global warming C. urgent need to protect the natural environment D. need to research into other uses of the trees in our forest