8 friction

friction
n
1 [U]
(a) rubbing of one surface or thing against another 摩擦
    Friction between two sticks can create a fire. 两个棍棒相互摩擦能起火.
(b) resistance of one surface to another surface or substance that moves over it 摩擦力
    The force of friction affects the speed at which spacecraft can re-enter the earth´s atmosphere. 摩擦力能影响航天器返回地球大气层的速度.
2 [U, C] disagreement or conflict between people or parties with different views 人或党派之间不同观点的矛盾或冲突
    There is a great deal of friction between the management and the work force. 劳资双方之间存在大量矛盾.
    conflicts and frictions that have still to be resolved 仍须解决的冲突和摩擦.