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.
Answer:
The greatest angle is 
Explanation:
According to angle sum property of a triangle, sum of all the angles of a triangle is equal to
°.
The given angles of a triangle are 
Therefore,
°
°
°

≈ 87.2°
≈ 71.8°
≈ 20.9°
Therefore, greatest angle is 
The English Channel is the body of water between England (Great Britain) and France, it is connected to the Atlantic Ocean.
Being a body of water, it can't be a water way - so the answer b) is false.
In fact, from the description above you know that the answer a. an extension of the Atlantic Ocean between England and France is true.
Answer:
Air, Animles
Explanation:
The Air helps us live, and the Animles help us in al kindes of ways. One is food, Happiness and many other things.
Answer:
<u><em>River valley civilizations</em></u>
Explanation:
They were centred around various river valleys as their main source of livelihood and the flourished only due tiote river valley on which they were based. Like the harappan in Indus Valley, The yellow river (Huang He), the Mesopotamia around Tigris and Euphrates and the egyptian Nile.