18. There is a widespread belief in the US 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 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 than their parents and
grandparents had 答案是 D
我有一个疑问，这里的动词补出都用的是had, 因为前面不是完成时，而是是适宜动词，所以我觉得应该用did 不过既然答案是D，我就想问一下，动词的补出是可以补出原动词的吗？ 例如 children eat more foods than their parents eat children eat more foods than their parents do 哪句对呢？还是都可以？ | 
