worth,worthy,worth-while都为adj.意为"值得".

　　1.worth：beworth+n.当名词为金钱时,表示"……值得……"

　　beworthdoingsth."……某事值得被做"

　　Thequestionisnotworthdiscussingagainandagain.

　　2.worthy：beworthyof+n.当名词为抽象名词时表示"……值得……"

　　beworthytobedone"某事值得被做"

　　Thequestionisnotworthytobediscussedagainandagain.

　　3.worth-while：beworth-whiletodosth"值得做某事"

　　worthwhile：Itisworthwhiledoingsth

　　Itisworthwhilesbtodosth.

　　典型例题

　　Itisnot____todiscussthequestionagainandagain.

　　A.worthB.worthyC.worth-whileD.worthwhile

　　答案C.由worth的用法可知,此句只适合词组beworth-whiletodosth..因此选C.