二、从逻辑关系词入手

常见的逻辑关系词有很多，如but, however, nevertheless, because, since, thus, so, in fact(可表示转折或者总结)等。假设待插入句子中出现了but之类表示转折的逻辑关系词，正确答案的前后一定是具有句意转折的，而且正确答案后边的句子是待插入句子but之后所要表达的意思，待插入句子是过渡句。其他逻辑关系可同理推断。如：

Many signals that animals make seem to impose on the signalers costs that are overly damaging. ■ A classic example is noisy begging by nestling songbirds when a parent returns to the nest with food. ■These loud cheeps and peeps might give the location of the nest away to a listening hawk or raccoon, resulting in the death of the defenseless nestlings.■ In fact, when tapes of begging tree swallows were played at an artificial swallow nest containing an egg, the egg in that “noisy” nest was taken or destroyed by predators before the egg in a nearby quiet nest in 29 of 37 trials.■

Look at the four squares [■] that indicate where the following sentence could be added to the passage.

The cheeping provides important information to the parent, but it could also attract the attention of others.

分析：

待插入句子中有but出现，所以正确答案前后一定是有句意转折的，正确答案的后边应该主要讲的是“吸引其他生物的注意”。根据逻辑关系判断，选项B为正确答案。

综上所述，托福阅读的插空题并不是没有方法可言的。希望阅读完本文后大家能有所收获，早日取得理想的成绩。

推荐阅读：

托福考试阅读答题方法

托福阅读3种题型要区别对待

如何备考托福阅读部分