【托福阅读题型：Speciation in Geographically Isolated　Populations句子插入题】托福阅读中句子插入题是重要题型之一。根据托福阅读题型不同来进行专项练习，是短期提高托福阅读能力的有效方法。同学们需要多加练习哦!

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　　托福阅读句子插入题：Speciation in Geographically Isolated　Populations

　　【Paragraph 4】Allopatric speciation can also be brought by the imperceptibly slow but colossal　movements of the tectonic plates that make up Earth’s surface. ■About 5 million years ago such geologic　movements created the land bridge between North America and South America that we call the Isthmus of　Panama. The formation of the isthmus had important consequences for global patterns of ocean water flow.　■While previously the gap between the continents had allowed a free flow of water, now the isthmus presented a　barrier that divided the Atlantic Ocean from the Pacific Ocean. ■This division set the stage for allopatric　speciation among populations of fishes and other marine species. ■(Speciation in Geographically Isolated　Populations)

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

　　The formation of the isthmus had important consequences for global patterns of ocean water flow.

　　Where would the sentence best fit?

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