Answer:
The Earth also gives us clues about the levels of greenhouse gases that existed in the past. For example, ancient air bubbles trapped deep in the ice of Greenland and Antarctica reveal how much carbon dioxide was present long ago.
Explanation:I learn it in 8 grade.
Valleys can be found in areas where there are alot of Mountains, Canyons can be found in places near rivers, plains are found in central North America, and Volcanoes can be found on islands.
Answer:
weather that is physically challenging
Explanation:
Primary source because it is the original copy of it. Hope this helps and have an awesome rest of your day!
