Not enough oxygen
rainforests will turn into desserts like the Sahara dessert which use to be a tropical place.
Primary sources can be described as those sources that are closest to the origin of the information. They contain raw information and thus, must be interpreted by researchers. Secondary sources are closely related to primary sources and often interpret them.
Drainage basin - the area of land drained by a river.
Catchment area - the area within the drainage basin.
Watershed - the edge of highland surrounding a drainage basin which marks the boundary between two drainage basins.
Source - the beginning or start of a river.
Confluence - the point at which two rivers or streams join.
Tributary - a stream or smaller river which joins a larger stream or river.
Mouth - the point where the river comes to the end, usually when entering a sea.
Hope this helped :)
Answer:

Explanation:
y=2x-5
y=mx+b
perpendicular = slope is -1
y=-1/2x+b
Passes throught 2,-5
-5=-1/2(2)+b
-5=-1+b
b=-4
y=-1/2x-4
Hope this helps!
Answer:
Layers that are less dense, such as the crust, float on layers that are denser, such as the mantle. Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. This is partly why the continents are at a higher elevation than the ocean floor.
Explanation: