198. Although Napoleon's army entered Russia with far more supplies than they had in their previous campaigns, it had provisions for only twenty-four days.
(A) they had in their previous campaigns
(B) their previous campaigns had had
(C) they had for any previous campaign
(D)in their previous campaigns
(E) for any previous campaign
答案是选E的，OG后面的解释我完全看不懂。
If than is followed by a clause referring to army, the subject of that clause must be singular (it). Furthermore, the verb of that clause will need to be in the past perfect form (had had) because it refers to a time before the simple past of entered. Finally, the preposition/or is more precise than in because supplies are gathered/or an upcoming campaign. Choices A and C incorrectly use the plural they and the simple past had. Moreover, A uses the less precise in. Choices D and E wisely dispense with the full clause and use a simple prepositional phrase. D, however, uses the imprecise in and the plural their. Only E, the best choice, avoids all the errors mentioned above.
有谁可以帮助下嘛？than后面要是单数，为啥？ | 
