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。想请教下，这里不是应该补出did么？为什么是had。
作者: wynn123 时间: 2010-1-10 18:46
had 要和have对应吧~选项里也没有did哦~