og264请教

264. Scientists believe that unlike the males of most species of moth, the male whistling moths of Nambung, Australia, call female moths to them by the use of acoustical signals, but not olfactory ones, and they attract their mates during the day, rather than at night.

(A) by the use of acoustical signals, but not olfactory ones, and they attract

(B) by the use of acoustical signals instead of using olfactory ones, and attracting

(C) by using acoustical signals, not using olfactory ones, and by attracting

(D) using acoustical signals, rather than olfactory ones, and attract（D）

(E) using acoustical signals, but not olfactory ones, and attracting

Choice D, the best answer, is concise, maintains parallel structure, and clearly conveys the comparisons being made between the two types of moth. In A and E, the comparison between most male moths and the male whistling moth is not clear. The use of but not does not clearly convey that most other moths use olfactory signals; rather than would be preferable, as well as parallel to rather than at night. In A, the phrase by the use of is unnecessarily wordy, and the insertion of they is not required. In E, the final verb should be attract (parallel to call), not attracting (parallel to using). Choice B violates parallelism with by the use of... instead of using, as well as with call... and attracting. Choice C distorts the meaning of the original with its suggestion that male whistling moths call female moths to them both by using acoustical signals and by attracting their mates during the day. The insertion of using in not using olfactory ones is unnecessary.

划红线的是什么意思啊？不怎么理解呀，BUT NOT 和RATHER THAN有什么区别吗？谢谢

划红线的是什么意思啊？

but not  没有清楚地表达most other moths use olfactory signals。

BUT NOT 和RATHER THAN有什么区别吗？

从这个例子看，个人认为but not只是强调the male whistling moths of Nambung not using olfactory signals, 而rather than不仅有这个意思，且还和前the males of most species of moth呼应，产生most other moths use olfactory signals这个意思。所以rather than 的意思表达更好。

我也是就事论事，其实做题时，不会有这种语感的。在没有其它差别和暗示时，还是公理有用，相同表达rather than最强。

NOT   A  BUT B 和B RATHER THAN A有差别.

RATHER THAN 相同的是instead of , but not, 或not等。我认为公理不是绝对的，但在多数情况下还是成立的。公理我记得不清。你可看刘振民的书，CD上有完全版。