[求助]想请教大牛一题

各位大牛，想请教此题该如何判断；另外，想请教如果遇到类似题目的话，该如何解决？谢谢！！

The Parthenon is larger than usual for a Doric temple, with eight columns on the short sides and seventeen on the long ones rather than the typical six and thirteen.

（A） usual

（B） is usual

（C） has been usual

（D） one usually is

（E） it is usual

答案为B

253. Analysts blamed May’s sluggish retail sales on unexciting merchandise as well as the weather, colder and wetter than was usual in some regions, which slowed sales of barbecue grills and lawn furniture.

(A) colder and wetter than was usual in some regions, which slowed

(B) which was colder and wetter than usual in some regions, slowing

(C) since it was colder and wetter than usually in some regions, which slowed

(D) being colder and wetter than usually in some regions, slowing（B）

(E) having been colder and wetter than was usual in some regions and slowed

Choice B is the best answer. It is concise and idiomatic, and which has a clear referent, the weather. In A, the insertion of was is unnecessary, and the referent of which is not clear because regions, not weather, is the nearest noun. In C, the adjective usual is needed in place of the adverb usually, and the referent of which is unclear because regions, not weather, is the nearest noun. In D and E, the verb phrases (being colder..., having been colder...) do not refer as clearly to the noun weather as the pronoun which does. Choice D needs the adjective usual in place of the adverb usually, while choice E fails to maintain parallelism in verb tense (having been... and slowed).

同意A，记得以前讨论过相似的一道题。

给个例句：

He was in a less jocular mood than usual...

谢谢几位高手，小妹还有一事相问，就是than可否当作关系代名词ㄋ？谢谢相助！