sentences: rolling on a surface is a kind of moving on a surface & the rubber ball is rolling across a surface -> the crack point is moving on a bottom the rubber ball is moving on a surface  the rubber ball is moving on a surface & a rubber ball is a kind of object & slip occurs when one preposition 's grass stay against each other -> friction will occur between the rubber ball and the surface friction will occur between the rubber ball and the surface  friction will occur between the rubber ball and the surface & a device point is a mean of preposition & friction causes the speed of an object to decrease -> friction will cause the speed of the rubber ball to decrease friction will cause the speed of the rubber ball to decrease  friction will cause the speed of the rubber ball to decrease & a device point is a mean of preposition & the object will stop when its speed is decreased to zero -> friction will cause the rubber ball to stop by decreasing the speed of the rubber ball to zero