【托福阅读题型：The History of Waterpower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!

　　查看全部：托福阅读题型分类练习之句子插入题

　　托福阅读句子插入题：The History of Waterpower

　　【Paragraph 3】Raising water and grinding corn were by no means the only uses of the waterpower mill, and during　the following centuries, the applications of waterpower kept pace with the developing technologies of mining, iron　working, paper making, and the wool and cotton industries. Water was the main source of mechanical power, and by the　end of the seventeenth century, England alone is thought to have had some 20,000 working mill. There was much　debate on the relative efficiencies of different types of waterwheels. ■The period from about 1650 until 1800 saw some　excellent scientific and technical investigations of different designs. ■They revealed output powers ranging from about 1　horsepower to perhaps 60 for the largest wheels and confirmed that for maximum efficiency, the water should pass　across the blades as smoothly as possible and fall away with minimum speed, having given up almost all of its kinetic　　energy. ■(They also proved that, in principle, the overshot wheel, a type of wheel in which an overhead stream of water　powers the wheel, should win the efficiency competition.) ■(The History of Waterpower)

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

　　The steam engine that turned the waterwheel was faulty and needed to be replaced.

　　Where would the sentence best fit?

　　答案见下一页：