crash   v.  ①碰撞，坠毁 wreck②破碎声 bang③失败，瓦解 break downThe car crashed into a tree. 车子猛撞在树上。

        The cause of the air crash has not been found out yet. 飞机失事的原因尚未查清。

clash n. 冲突，指势力相当的双方冲突，是战争的含蓄说法。

       The clash of arguments between them is unavoidable. 他们争论时，双方的冲突是不可避免的。

        A border clash between the two armies started the war. 两军的边境冲突是这场战争的导火线。