下面的英文部分是我在一个英语论坛上找到的,再加上我的中文回答,相信可以解决这个问题.
Dear native teachers,
One afternoon,while checking a project,one of the reviewers hollered out,"Does anyone know what ravel means?" As usual,someone had an opinion and replied,"to separate or disentangle,to take apart or undo."
That got everyone's attention,and the question arose,"Isn't that the meaning of unravel?Isn't ravel different than unravel?" After 10 minutes of debate and discussion,we resorted to looking it up in Webster's dictionary.And guess what we found out?That "ravel" means "to unravel"!Of course,that caused an uproar!
We had to lookup the prefix "un-" which meant what everyone thought it meant,a prefix meaning "not."
And,how come the same word (to wit "ravel") can have,not just different meanings,but totally opposite!
So I fear this is just one of the idiosyncrasies(怪癖) of the English language,which is what makes it so fascinating.
我自己的总结：有时加UN,不一定是反义词.
而且还有个很有趣的事：ravel这个词有两个完全相反的意思.一个是解开,另一个却是弄混.
unravel只有一种意思,就是解开.
所以说这两个词确实是很有意思的词.相互矛盾的东西却统一在一个单词里面了.