LZM的更多错误

以下是引用remeo在2003-10-6 20:36:00的发言：
129. In an effort to reduce their inventories, Italian vintners have cut prices; their wines have been priced to sell. and they are.
(A) have been priced to sell, and they are
(B) are priced to sell, and they have
(C) are priced to sell, and they do
(D) are being priced to sell, and have
(E) had been priced to sell, and they have
In choice C, the best answer, do is correctly used in place of the full verb do sell; in this verb, do is a conjugated form and sell is in the infinitive form, corresponding to its previous use in the sentence (in the phrase priced to sell). In choice A, the omitted word is selling; in B, D, and E, it is sold. Neither of these forms corresponds properly to to sell earlier in the sentence. Also, in E, the past perfect had been priced signifies that the wines had been priced to sell before the prices were cut.

这种代词指代不一致的现象确实很少见，我也不明白为什么可以这么用，哪位牛牛来解释一下？
另外对a, they originally seemed 的解释我也不是很清楚。