grip,grasp,grab差在哪里?

grip的意思是"take and keep a firm hold of sth"对应的汉语意思是"紧抓(某物/某人),紧握"
grasp的意思是"seize(sb/sth)firmly with hand(s),finger(s),teeth,etc.对应的汉语意思是"抓住或咬住(某人/某事物)
grab的意思是"grasp sth suddenly or roughly;snatch sth selfishly or rudely 对应的汉语意思是"抢;抓;抢夺"