Which of the following compound is not degraded by any biological process?

The surface of the earth covered with water is 

Ozone hole was first observed over

Which one of the following is not an air pollutant?

Which of the following does not contain nitrogen?

.............. of air, water and soil affect the quality of life and ......... the biodiversity.

We need to ........ our natural resources and use them in a .......... manner.

Various man-made compounds such as ........ cause depletion of ozone layer.

The nitrogen-fixing bacteria found in the roots of legumes in special structures called as root .........

Eukaryotic cells and many prokaryotic cells need oxygen to breakdown .......... molecules and get energy for their activities.

State any two harmful effects of air pollution.

Name any two environmental problems caused by various activities of human beings.

Do all organisms require water? Give reasons.

What are the methods of preventing or reducing soil erosion?

List four points which one should know regarding cycling of materials.

What is the difference between nitrification and denitrification?

What are the sources of water pollution?

List three major factors which lead to water pollution. Give examples.

How addition of undesirable substances and change in temperature affect the water the life?

Why is replenishment of forests necessary?

What will happen, if decomposers are eliminated completely from the earth surface?

Is it necessary to replenish forests?

April 22, is celebrated by countries all over the world as the Earth Day clean Delhi took the initiative and organised Saving the greens campaign.
Equipped with gloves,rakes,gunny, bags and a lot of enthusiasm,students  assembled at a park on the Ridge and took upon themselves the task of cleaning the Ridge. Activities that were carried out included picking up all the polybags that were littering a part of the ridge and removing advertisements nailed to trees.disturbing pamplets at the crossing to passersby In about on hours time the children managed to collect about 20 large gunny bags full of plastic
Answer the following questions based on above information
(a) What are messages sent by their activity to the public of Delhi?
(b) What is your suggestion?
(c) Which values are displayed by the childrean?