What causes friction? A. Inertia

B. Tiny collisions, called microwelds, on surfaces, even those that

seem smooth

C. Action - Reaction

D. All surfaces are rough to the touch and therefore cause friction

The best answer all surfaces are rough to the touch and therefore cause friction bcz when two surfaces are on each other there is formation of cold welds which increases friction

Explanation:

I hope this will help you :)

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.