Our Home Earth, a Unique Life-Sustaining Planet

Why is Earth often called our "home"?

1. It is the only planet with mountains.
2. It provides all the conditions necessary for life.
3. It is made entirely of water.
4. It has the strongest gravity in the Solar System.

Which of the following is an example of conserving natural resources?

1. Wasting electricity
2. Leaving taps running
3. Using solar energy
4. Burning more coal

Why is soil important for life on Earth?

1. It reflects sunlight only.
2. It supports plant growth and provides nutrients.
3. It produces oxygen directly.
4. It prevents rainfall.

Which human activity contributes most to global warming?

1. Planting trees
2. Burning fossil fuels
3. Rainwater harvesting
4. Recycling paper

Which sphere of Earth includes rivers, lakes, oceans, and groundwater?

1. Atmosphere
2. Lithosphere
3. Hydrosphere
4. Biosphere

Which of the following protects Earth from harmful ultraviolet (UV) rays?

1. Carbon dioxide layer
2. Nitrogen layer
3. Ozone layer
4. Water vapour

Which process continuously recycles water on Earth?

1. Nitrogen cycle
2. Carbon cycle
3. Water cycle
4. Rock cycle

Which natural resource is essential for drinking, agriculture, and industry?

1. Air
2. Water
3. Soil only
4. Rocks

Which layer of Earth contains all living organisms?

1. Lithosphere only
2. Atmosphere only
3. Biosphere
4. Hydrosphere only

Which gas is essential for respiration in humans and animals?

1. Nitrogen
2. Oxygen
3. Carbon dioxide
4. Helium

Which gas makes up the largest portion of Earth's atmosphere?

1. Oxygen
2. Carbon dioxide
3. Nitrogen
4. Hydrogen

Why is Earth called a unique life-sustaining planet?

1. It is the largest planet in the Solar System.
2. It has suitable conditions that support life.
3. It is the closest planet to the Sun.
4. It has no atmosphere.