Question

about seventy percent of the earth’s surface is covered with water and is called the _______.
a) biosphere
b) lithosphere
c) hydrosphere
d) stratosphere

the part of the earth where life exists is the _______.
a) biodome
b) biosphere
c) hemisphere
d) atmosphere

a _______ can slope away from a land mass underwater for as much as 800 miles (1,287 km) in some areas of the world.
a) continental trench
b) continental ridge
c) continental shelf
d) continental drift

Explanation:

First Question

• Option A: Biosphere is the zone of life on Earth, including land, water, and air, not just water - covered areas.
• Option B: Lithosphere is the rigid outer part of the Earth, including the crust and upper mantle, related to land and rock, not water.
• Option C: Hydrosphere is defined as all the water on Earth's surface (oceans, lakes, rivers, etc.), and about 70% of Earth's surface is water, so this matches.
• Option D: Stratosphere is a layer of the atmosphere, not related to the water - covered part of Earth's surface.

• Option A: Biodome is a man - made or natural enclosed area with a specific ecosystem, not the entire region where life exists on Earth.
• Option B: Biosphere is the global sum of all ecosystems, the part of Earth where life exists (including land, water, and atmosphere).
• Option C: Hemisphere is half of a sphere, usually referring to half of the Earth (e.g., Northern Hemisphere), not the area of life.
• Option D: Atmosphere is the layer of gases surrounding Earth, only a part of the biosphere.

• Option A: Continental trench is a deep depression in the ocean floor, usually at subduction zones, not a sloping area from a land mass underwater.
• Option B: Continental ridge is an underwater mountain range, not a sloping area from a land mass.
• Option C: Continental shelf is the area of seabed around a large landmass where the sea is relatively shallow compared to the open ocean, and it slopes away from the land mass underwater, and can extend for long distances (up to 800 miles in some areas).
• Option D: Continental drift is the theory that continents move over time, not a physical feature of the ocean floor.

Answer:

C) hydrosphere

Second Question