protect,prevent,preserve 的区别

protect,prevent,preserve 的区别 求：preserve ,defend ,protect ,prevent的区别和各自用法.详 请问 protect defend guard preserve的区别 preserve sb.和protect sb.的区别 protect 与 prevent的区别 如何区别protect和preserve prevent和protect区别 protect prevent 有什么区别? 求protect,prevent,defend+sb from doing的区别 preserve&reserve 的区别 preserve reserve的区别 protect和preserve都有保护的意思,两者用法上有什么区别