27.  Most of the country's biggest daily newspapers had lower circulation in the six months from October 1995 through March 1996 than a similar period a year earlier.
【正确答案】 C
【答案解析】 Logical Predication; Parallelism
   The sentence compares newspaper circulation during two separate periods, but the comparison is not parallel because it has been drawn using a prepositional phrase, in the six months, and a noun phrase, a similar period. Both phrases compared by than should be prepositional phrases: lower in the six months... than in a similar period.
   A   In the six months and a similar period are not grammatically parallel. The sentence appears illogically to compare a period of time with an amount of circulation.
   B   In the six months and a similar period's are not grammatically parallel.
   C   Correct. In the six months and in a similar period are both prepositional phrases, making the comparison clear and properly idiomatic.
   D   In the six months and that in a similar period are not grammatically parallel; it is unclear what the antecedent of that is supposed to be.
   E   In the six months and that of a similar period are not grammatically parallel; it is unclear what the antecedent of that is supposed to be.
   The correct answer is C.