D. Obviously because it was large and they didn't have a lot of supplies to go across also it was very deep.
Answer:
The cities have a much larger populations in smaller areas, which can cause more crime and overcrowding, along with pollution.
Tundras and deserts have a number of similarities such as their lack of water or how organisms that inhabit them are have special features to survive their extreme weather. Both are nearly unsustainable for human life and have just like the tundra, deserts have freezing temperatures at night.
The answer is C, a volcanic eruption
