worth of 有哪些使用规则？

worth,worthy,worth-while都为adj. 意为"值得". 

1. worth： be worth + n. 当名词为金钱时,表示"?? 值得??" 
be worth doing sth. "??某事值得被做" 
The question is not worth discussing again and again. 

2. worthy：be worthy of +n. 当名词为抽象名词时表示"??值得??" 
be worthy to be done "某事值得被做" 
The question is not worthy to be discussed againand again. 

3. worth-while： be worth-while to do sth "值得做某事" 
worth while： It is worth while doing sth 
It is worth while sb to do sth. 

典型例题 

It is not ____ to discuss the question again and again. 
A.worth B.worthy C.worth-while D.worth while 
答案C. 由worth的用法可知,此句只适合词组be worth-while to do sth..因此选

worth 在句中 与 表示时间的短语 连用，在柯林斯词典里作如下解释：
【COMB in QUANT Worth combines with time expressions, so you can use worthwhen you are saying how long an amount of something will last. 可维持 (一段时间) 的东西】
例：

a week's worth of food 可够你吃一周的食物
You've got three years' worth of research money to do what you want with.
你有 可维持3年的研究经费 来做你想做的事情。

所以，问题中的句子last time I had two weeks' worth of weightlifting in three days and I hurt myself.应该是如下含义：【上次，我在三天内完成了两周才能做完的举重练习（超负荷锻炼），所以我把自己搞受伤了。】

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