Answer:
It killed many crops.
Explanation:
The dust bowl ruined many lands and destroyed agricultural production.
Answer:
d. The Indus river was completely within the boundaries of the Persian Empire, Alexander's conquests, and Mauryan Empire
Explanation:
The Indus river is located in what it is Pakistan these days. It is the only river that was completely within the boundaries of the Persian Empire which include parts of current Pakistan, Alexander's conquests which included territories from Macedonia until parts of India, and also Mauryan Empire that included parts of current Pakistan up to some parts of current Bangladesh. The river Ganes, Krishna and Brahmaputra were part of the Mauryan Empire however, they are not included in the Persian Empire or of Alexander's conquests.
Answer:
1. They usually host three or more ecosystems where animals can’t live.
4. They usually host one ecosystem with a variety of plants
Explanation:
A mountain ecosystem has more than one ecosystem. This is mainly due to the diversity of climate that this environment promotes. Due to its proximity to the ocean, slope and elevation, the mountain ecosystem promotes different areas that create different ecosystems, some more humid and others drier.
In this environment there is usually a wide variety of plants, but not animals.
River valley trade made them key economic areas.
Hope this helped. :)