六級考試的閱讀理解部分中有許多難以辨識或是容易混淆的選項，許多考生在看到某個選項與原文內容類似的時候往往搖擺不定，無法做出正確的判定，偷換概念這類錯誤類型便是非常容易造成考生錯誤的選項，它的命制方式是將原文某處的語句中，換掉其中的一部分，從而造成選項中的信息與原文並不匹配，而學生之所以容易被這類錯誤迷惑，究其原因是因為許多學生並沒有仔細對應定位處和選項，並認真分辨其中的同義替換，而是讀完文章後僅憑文章在頭腦中的印象做出判定，從而造成失分，以下是真題中幾個典型的例子，供學生參考。
例1
It was the worst tragedy in maritime (航海的) history, six times more deadly than the Titanic. When the German cruise ship Wilhelm Gustloff was hit by torpedoes (魚雷) fired from a Russian submarine in the final winter of World War II, more than 10,000 people - mostly women, children and old people fleeing the final Red Army push into Nazi Germany - were packed aboard. An ice storm had turned the decks into frozen sheets that sent hundreds of families sliding into the sea as the ship tilted and began to go down. Others desperately tried to put lifeboats down.
22. Hundreds of families dropped into the sea when
A) a strong ice storm tilted the ship
B) the cruise ship sank all of a sudden
C) the badly damaged ship leaned toward one side
D) the frightened passengers fought desperately for lifeboats
根據原文信息，Wilhelm Gustloff這艘巡洋艦被魚雷擊中後，一陣冰風暴將甲板凍住，隨著船體開始傾斜，人們滑到海裡。題幹問到這些人什麼時候落入水中，我們應該通過題幹中的dropped into the sea回到原文定位到sent hundreds of families sliding into the sea as the ship tilted and began to go down，根據這樣的信息，選項C中的leaned一詞是原文中tilted的同義替換，而the ship同the badly damaged ship一致，因此C選項作為原文的同義替換，成為正確答案。
典型錯誤：許多同學錯選了A選項a strong ice storm tilted the ship，因為a strong ice storm和tiled the ship都是文中出現過的信息，通過拼湊，許多同學沒有作出準確的辨別。此處的a strong ice storm是被偷換的內容，如果要正確，此處應當是torpedoes (魚雷) fired from a Russian submarine，也就是說，出題人通過將一個正確句子中的某處偷換為另一個文中曾出現過的信息，從而造成學生失分。
例2
The long silence about the sinking of the Wilhelm Gustloff was probably unavoidable - and necessary. By unreservedly owning up to their country's monstrous crimes in the Second World War, Germans have managed to win acceptance abroad, marginalize (使...不得勢) the neo- Nazis at home and make peace with their neighbors. Today's unified Germany is more prosperous and stable than at any time in its long, troubled history. For that, a half century of willful forgetting about painful memories like the German Titanic was perhaps a reasonable price to pay. But even the most politically correct Germans believe that they' ye now earned the right to discuss the full historical record. Not to equate German suffering with that of its victims, but simply to acknowledge a terrible tragedy.
25. It can be learned from the passage that Germans no longer think that
A) they will be misunderstood if they talk about the Wilhelm Gustloff tragedy（正確答案）
B) the Wilhelm Gustloff tragedy is a reasonable price to pay for the nation's past misdeeds
C) Germany is responsible for the horrible crimes it committed in World War II
D) it is wrong to equate their sufferings with those of other countries
典型錯誤：選項B中的信息the Wilhelm Gustloff tragedy是文中很重要的核心概念，全文都是通過這件事情展開的，而a reasonable price to pay for the nation's past misdeeds則是最後一段中出現過的內容，學生很容易造成先入為主的認為這場悲劇是德國人應當承擔的代價，而作者所表達的觀點並非如此，德國人應當承擔的代價是a half century of willful forgetting，也就是他們承擔的代價並不是災難本身，而是半個世紀多的時間裡對這場災難有意的遺忘。
這類錯誤在考試時非常容易造成考生失分，希望大家通過平時的練習，可以有效地加強自己識別選項的能力，順利通過六級考試。