fasten: implies an action such as tying, buttoning, nailing, locking, or otherwise securing: ~ed the horse to a post.    (tie线绳a piece of string or cord还表示领带领结，或系，如tie his shoelace系鞋带     button扣子，如he buttoned up his jacket他扣上了夹克衫   nail钉子或钉上，如nail a notice on [to] the door把通知钉在门上lock锁或锁上，如the safe locks easily保险柜容易锁上，如lock the door when you leave你离开时把门锁上)        （secure表示固定系牢，即不容易移动to fix or attach something firmly so that it cannot be moved or lost, 如pins secure the handle to the main body固定销把手柄牢牢地固定在主体上，如doors are well secured at night夜里门锁得严严实实，如she secured the boat with a rope她用绳子把船拴住了)


fix: usually implies a driving in, implanting, or embedding in an attempt to secure something: ~ the stake in the earth.     (drive除了驾驶驱使，还表示敲击to hit，如drive a nail into sb.'s coffin促使某人早死，如drive a wedge between造成隔阂，如drive a nail into a piece of wood把钉子钉进一块木头)    embed嵌入，是指将一个物体放入另一个物体to fix something firmly into a substance or solid object，如腿里的玻璃，墙里的子弹，根深蒂固的偏见，玩具里的芯片


attach: suggests a connecting or uniting by or as if by a bond, link, or tie in order to keep things  together: ~ the W-2 form here.    （attach本意是用线连接，如the worker attached a cable工人连接电缆，习语no strings attached表示无附加条件，attachment还表示邮件附件）


affix: implies an imposing of one thing on another by such means as gluing, impressing, or nailing:  ~ your address label here.   impose加到上边


fasten固定: 泛指固定，如系扣钉锁上，fix固定: 通常指敲插嵌入等，attach系上附上: 表示用带链绳等连接联合，affix附上: 通常指把小东西附加到大东西上(如邮票到信封)，如粘压钉


记忆方法: 1）首字母FFAA想成2AF安放<==固定

         2）固定的意思是使牢固位于mean to make something stay firmly in place.