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.worth B.worthy C.worth-while D.worthwhile
答案C.由worth的用法可知，此句只适合词组beworth-whiletodosth.。因此选C。
