Question

types of friction
static friction -
sliding friction -
friction is the force that _____________ the
sliding motion of two _____________ surfaces
and is caused by microscopic bumps on surfaces
called ____________________.
rolling friction -
fluid friction -

Explanation:

Friction opposes the relative motion between two surfaces. When two surfaces are in contact and one tries to slide over the other, friction acts to resist this motion. The microscopic bumps on surfaces are called asperities.

Answer:

opposes, touching, asperities