(A) would fail if the density of the timber wolf population in that region is more numerous than

(B) would fail provided the density of the timber wolf population in that region is more than

(C) should fail if the timber wolf density in that region was greater than

(D) will fail if the density of the timber wolf population in that region is greater than

(E) will fail if the timber wolf density in that region were more numerous than

D, the best choice, uses a correct sequence of present and future indicative verb forms--predicts, will fail, and is--in the three related clauses. Density, an abstract "mass" noun, is logically construed with greater than. In A and B, would fail disagrees with the other verbs in tense and mood. Choice A misconstrues density with more numerous than, and B uses the pretentious and illogical word provided for ifm a conditional clause after a negative idea (would fail). C's should fail and was are confusing and inconsistent with predicts. C and E use the absurd phrase timber wolf density. (The wolves are not dense; their population is dense.) E also uses an inconsistent subjunctive form, were, and misconstrues density with more numerous than.

can you tell me the use of one? thanks

one表示定指, 就指固定的那么一个, 可以参见OG134对于C的解释.

og134里的one特指就是那么一个，没有其他的另一个，表示强调。

og161里的one是特指the density (of the timber)的范围么？就是说狼的density?

one表示就那么一个, 和a不同, a可以表示一种泛指, 不一定就是数量上的一个, 但是one出现必然是指数字上的一, 而且这个还有特指的意为.