oG47，请教牛牛

bruceala

47. Displays of the aurora borealis, or "northern lights," can heat the atmosphere over the arctic enough
        to affect the trajectories of ballistic missiles, induce electric currents that can cause blackouts in some areas and corrosion in north-south pipelines.

1. to affect the trajectories of ballistic missiles, induce

2. that the trajectories of ballistic missiles are affected, induce

3. that it affects the trajectories of ballistic missiles, induces

4. that the trajectories of ballistic missiles are
                   affected and induces （E）

5. to affect the trajectories of ballistic missiles and
                   induce

E中的induce 到底与affect并列还是和can heat中的heat并列，明显产生了歧义，为何不能就此而排除E？

  是不是应该理解为，如果是和affect并列，那么and前面就肯定有一个to，但是这里没有，所以应该肯定是和heat并列？

  但是og中的解释是，and 前面的to省略，那么，induce就是和affect并列的，如果是这样并列，那么必然产生歧义，E就为错误答

gonghao

是这样：

不定式的并列中，如果使用and连接的话

第一个不定式的to不能省略，第二个不定式的to则可以省略

即to do A and do B=to do A and (to) do B

gracie495824

那么请问，什么时候to可以省略，什么时候不能省略呢？

比如OG11－65就没有省略

65.   The only way for growers to salvage frozen citrus is to process them quickly into juice concentrate before they rot when warmer weather returns.

(A) to process them quickly into juice concentrate before they rot when warmer weather returns

(B) if they are quickly processed into juice concentrate before warmer weather returns to rot them

(C) for them to be processed quickly into juice concentrate before the fruit rots when warmer weather returns

(D) if the fruit is quickly processed into juice concentrate before they rot when warmer weather returns

(E) to have it quickly processed into juice concentrate before warmer weather returns and rots the fruit

Parallelism + Agreement

Parallelism requires that the same word forms perform the same functions in the sentence. Here, the linking verb is requires two infinitives: to salvage ... to process (or to have ... processed). A pronoun must match the noun it refers to. Citrus is singular and requires the singular pronoun it, not the plural pronouns them and they.

A     Citrus does not agree with them and they

B      If they are quickly processed is not parallel to the infinitive to salvage, they does not agree with citrus

C     For them to be processed quickly is not parallel to the infinitive to salvage, them does not agree with its reference

D     If the fruit is quickly processed is not parallel to the infinitive to salvage; they does not agree with fruit

E      Correct. This sentence has correct parallel infinitives and uses the words it and fruit to refer unambiguously to citrus. The use of before rather than when also clearly establishes the cause-and-effect relationship between weather and rotting.

The correct answer is E.

对于不定式中to的省略问题很困惑啊，拜请大牛指导！！！～～～

batmanhm

SC只考虑最优选项，没有绝对正确啦

47. Displays of the aurora borealis, or "northern lights," can heat the atmosphere over the arctic enough
        to affect the trajectories of ballistic missiles, induce electric currents that can cause blackouts in some areas and corrosion in north-south pipelines.

1. to affect the trajectories of ballistic missiles, induce

2. that the trajectories of ballistic missiles are affected, induce

3. that it affects the trajectories of ballistic missiles, induces

4. that the trajectories of ballistic missiles are
                   affected and induces （E）

5. to affect the trajectories of ballistic missiles and
                   induce

B/C/D肯定错，A中的induce用法错，这时歧义肯定不考虑了