Fossil fuels form in sedimentary rocks when-
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heat and pressure applies to the fossils.

Explanation:

Fossil fuels are made of the remains of old organisms that were buried under layers of sediments many many years ago.

Explanation:

nanotechnology is a powerful tool in biomaterials research as it creates numerous possibilities for the engineering of functional molecules. nano-bio refers to projected ability to incorporate biomimicry into various materials at nanoscale.  

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.