sentences: a human is a kind of object & a child is a kind of young human ->  a child is a kind of object  a child is a kind of object & friction is a kind of force & low friction can cause an object to slip ->  a low frictional force can cause a child to slip  a human is a kind of object & a child is a kind of young human ->  a child is a kind of object  a low frictional force can cause a child to slip & a child is a kind of object & the surface of ice exerts low friction on objects on it ->  a child can slip more easily on the surface of ice  a child can slip more easily on the surface of ice & friction is a kind of force & as friction increases, the chance of slipping will decrease -> an increase in friction will decrease the chance of a child slipping