请教PREP2-25题！！！！！！

There is a widespread belief in the United States and Western Europe that young people have a smaller commitment to work and a career than their parents and grandparents and that the source of the change lies in the collapse of the "work ethic."

(A) a smaller commitment to work and a career than their parents and grandparents

(B) less of a commitment to work and a career than their parents and grandparents

(C) a smaller commitment to work and a career than that of their parents and grandparents

(D) less of a commitment to work and a career than their parents and grandparents had

(E) a lessening of the commitment to work and a career that their parents and grandparents had

答案是D 为什么补助动词had? 我觉得要补助动词应该补DID呀 请高手赐教！

还有 less of a commitment 可以这么用吗？如果可以的话 后面应该怎么写？感激！

我觉得这里的had 和did都对。。

首先就看你吧have当作一个什么看待了。

I havenn't a sister =I donn't have a sister.

这里明显把have当作了类似Be动词的类型。。

have less of=更加少。。

这里had不当助动词来看啊,就是把实意动词再重复说了一遍,加以时态的变化

个人觉得如果不用had,补did也是可以的

同问:less of a commitment 这个用法怎么理解,觉得怪怪的

楼上的

less of 表示程度

具体可以查LDOCE

同意. 好象之前在哪道题里也有过类似的讨论...后来LES前辈这么总结的.

所以这题我选了B. 因为找不到did, 我想既然跟前面的have意思一样, 是不是就可以省略了. 请问, 这样的省略会造成什么样的歧义?