Soil that remains frozen for at least two consecutive years

Soil that remains frozen for at least one consecutive year

Soil that remains frozen for at least three consecutive years

Soil that remains frozen for at least four consecutive years

Polar regions

High-altitude regions

Subarctic regions

All of the above

0°C

-10°C

-20°C

-30°C

1-2 meters

10-20 meters

100-200 meters

1,000-2,000 meters

Soil

Ice

Rocks

All of the above

It stores carbon

It releases carbon

It regulates the global temperature

All of the above

It is causing permafrost to melt

It is causing permafrost to freeze

It is having no impact on permafrost

It is causing permafrost to expand

Release of greenhouse gases

Changes in ecosystems

Coastal erosion

All of the above

A forest that is located between the tropics and the polar regions

A forest that is located between the tropics and the subtropics

A forest that is located between the subtropics and the polar regions

A forest that is located between the tropics and the temperate regions

Warm and humid

Cold and dry

Moderate and humid

Moderate and dry

Oak

Maple

Birch

All of the above

Deer

Bear

Wolf

All of the above

Deforestation

Climate change

Pollution

All of the above

Reduce deforestation

Mitigate climate change

Reduce pollution

All of the above

Permafrost is found in the temperate forest

The temperate forest is found in permafrost regions

Permafrost and the temperate forest are not related

Permafrost and the temperate forest are both found in polar regions