教學(xué)過(guò)程中經(jīng)常遇到學(xué)生對(duì)于長(zhǎng)難句的分析和理解不到位的情況，長(zhǎng)難句的分析和理解會(huì)影響學(xué)生在托福閱讀的理解，尤其是在句子簡(jiǎn)化題。這次題目解析針對(duì)于TPO的一個(gè)長(zhǎng)難句：

　　Sediments are also dropped where a river slows on entering a lake or the sea, the deposited sediments are on a lake floor or the seafloor at first, but will be located inland at some future date, when the sea level falls or the land rises; such beds are sometimes thousands of meters thick.

　　難句類型： 復(fù)雜修飾+插入成分

　　本句的主句結(jié)構(gòu)應(yīng)當(dāng)是Sediments are also dropped，but will be located inland at some future date; such beds are sometimes thousands of meters thick. 這是一個(gè)由分號(hào)隔開(kāi)的并列句，分號(hào)前面的句子結(jié)構(gòu)比較復(fù)雜，Sediments are also dropped ，后面跟了一個(gè)由where引導(dǎo)的狀語(yǔ)從句，緊接著這個(gè)狀語(yǔ)從句又加上了一個(gè)插入結(jié)構(gòu)， the deposited sediments are on a lake floor or the seafloor at first， 然后才開(kāi)始進(jìn)行轉(zhuǎn)折but will be located inland at some future date， 但是馬上又跟上了一個(gè)由when 引導(dǎo)的狀語(yǔ)從句。分號(hào)后面的半句比較簡(jiǎn)單 such beds are sometimes thousands of meters thick.同學(xué)們面對(duì)這樣的句子一定要先找主干，把狀語(yǔ)從句、插入結(jié)構(gòu)紛紛跳過(guò)，從紛繁復(fù)雜的句子中找出主干來(lái)，才能不被ETS出題人改寫的句子所迷惑。

　　譯文：

　　當(dāng)河流匯入湖泊和海洋的時(shí)候也會(huì)有沉淀，這些沉淀最初在湖底或海底，但將來(lái)海平面下降或者陸地崛起時(shí)，它們就會(huì)分布于內(nèi)陸，通常厚達(dá)幾千米。

　　意群訓(xùn)練：

　　Sediments are also dropped where a river slows on entering a lake or the sea, the deposited sediments are on a lake floor or the seafloor at first, but will be located inland at some future date, when the sea level falls or the land rises; such beds are sometimes thousands of meters thick.