Available Answers

1. 1.

   Why is our planet called the watery planet?

2. 2.

   Discuss the importance of each sphere of the environment.

3. 3.

   We must protect our environment and keep it clean. What are some ways in which you can do so?

4. 4.

   Choose the correct answer.

   1. What per cent of earth is covered by land?
      1. 71 per cent
      2. 29 per cent
      3. 40 per cent
      4. 20 per cent
   2. Which of these are the main sources of fresh water?
      1. Rivers
      2. Lakes
      3. Ponds
      4. All of these
   3. Which of these help in the formation of clouds?
      1. Oxygen
      2. Water vapour
      3. Nitrogen
      4. All of these
   4. Which is the most important gas for our survival?
      1. Oxygen
      2. Nitrogen
      3. Argon
      4. Hydrogen
   5. What is the layer below the crust known as?
      1. Mantle
      2. Inner core
      3. Outer core
      4. Layer
5. 5.

   Match the columns.

   A	B
   1. Nitrogen	a. Living organisms exist
   2. Argon	b. 78 per cent
   3. Oxygen	c. Other gas present in atmosphere
   4. Lithosphere	d. 21 per cent
   5. Biosphere	e. Also called crust

    

6. 6.

   Fill in the blanks.

   1. Our ______________ is the natural world in which people, animals and plants live.
   2. Our environment consists of ______________ spheres.
   3. The ______________ includes all water bodies.
   4. ______________ is the gaseous layer surrounding the earth.
   5. ______________ is needed by the plants for making food.