请教OG SC 258

258. The British sociologist and activist Barbara Wootton once noted as a humorous example of income maldistribution that the elephant that gave rides to children at the Whipsnade Zoo was earning annually exactly what she then earned as director of adult education for London.

(A) that the elephant that gave rides to children at the Whipsnade Zoo was earning

(B) that the elephant, giving rides to children at the Whipsnade Zoo, had been earning

(C) that there was an elephant giving rides to children at the Whipsnade Zoo, and it earned

(D) the elephant that gave rides to children at the Whipsnade Zoo and was earning（A）

(E) the elephant giving rides to children at the Whipsnade Zoo and that it earned

请问答案A中为什么说the elephant....was earning...为什么不用the elephant ....earning

that the elephant that （gave rides to children at the Whipsnade Zoo） was earning

这个that要求用完全的谓语动词。

能解释得更具体点吗？什么叫做完全的谓语动词？？

这题用了倒装，即once noted (that the elephant.......for London) as a example of maldistribution...此题把note的从句宾语滞后了，所有选项里只有A和B符合。

用从句而不用分词表示这是个已经发生的动作，另外用完成时没有依据，所以选A，至于为何要用进行时态，我也说不清楚，大概表示没有学会之前一直在进行的动作吧。。。。

想问问，如果说THAT需要完全的谓语动词，为何WAS EARNING不用EARNED？？不是更好吗？

拜托拉，为什么没有人回答我呢？？？