0505的3道语法问题~~ 谢谢大家了~~

iamaboy228UID: 2116956

3. Royal jelly, a secretion produced by worker bees, is fed to------- destined to become queen bees.
(A) those that
(B) be those
(C) those of
(D) those
答案是D,请高人解释一下~~  
我选的为A,也请指明错误在哪~~  谢~~

13. The illusion of motion pictures rests on the eyes* tendency-------an image for a fraction of a second after the image has been withdrawn.
(A) to retain
(B) that retaining
(C) to be retained
(D) has retained
答案为C,请说明一下~~

20. (By the) 1880’s, (world)( demand for) cotton had begun (fall) off.
为何选D 如何改~~~

谢谢大家帮我说明一下~~  谢谢~~

funny68UID: 192763

原帖由 iamaboy228 于 2006-1-8 22:26 发表
3. Royal jelly, a secretion produced by worker bees, is fed to------- destined to become queen bees.
(A) those that
(B) be those
(C) those of
(D) those
答案是D,请高人解释一下~~  
我选的为A,也 ...

２ illusion 当然是被反映到人的眼睛里
３　To fall
1 those 是代词啊做表语后面的　过去分词修饰他