og83--百思不解?

83. Any medical test will sometimes fail to detect

a condition when it is present and indicate that there is one when it is not.

(A)  a condition when it is present and indicate that there is one

(B)  when a condition is present and indicate that there is one

(C)  a condition when it is present and indicate that it is present

(D)  when a condition is present and indicate its presence

(E)   the presence of a condition when it is there and indicate its presence

Only choice C, the best answer, produces a sentence in which every pronoun it refers clearly and logically to the noun condition. In choices A and B, the phrase indicate that there . is one does not grammatically fit with when it is not because it has no referent. Choices B and D are imprecise in saying that a test will fail to detect when a condition is present, since the issue is the presence and not the timing of the condition. Further, its presence in D leaves the it in when it is not without a logical referent: it must refer to condition, not presence. Choice E repeats this error; also, the presence ... when it is there is imprecise and redundant.

两个问题:

1.In choices A and B, the phrase indicate that there . is one does not grammatically fit with when it is not because it has no referent.是为什么?

2.是否允许两个不同代词指代相同的东西, 如这题的condition被one和it指代?

感谢!!!

1. there is one when it is not

这里 it 不能指代 one, 两个都是 pron. 所以 it 指代不明。

不要把这个 it 放到整个句子中去理解，就 A 而言，it 出现在 that 从句中，要就近分析其指代。

2. one 不能指代 condition

1.但是正确答案是it指代也是传递着指代啊？

2.one为什么不能指代condition呢？

再请教！

感谢！

个人觉得detect后面不应该直接加名字做动宾关系

而应该用一个when的从句比较合适

不知道时候解释的通

代词分两类: 1. 象 it/he/they 这种是特定代词, 一定有指代对象表明他的出处. 2. 不定代词, 比如one/ones.

这两种代词在同一句句子里指代同一个对象的时候会有问题, 所以最好不要混用, 而是保持一致. 前面用it, 后面也用it.