Their brain is 28 tricked into thinking they are eating more than they really are.
答案：(D) therefore
前面說食物的視覺大小被放大、手的大小維持正常，這句「因此」，大腦被騙以為吃得比實際多，therefore（因此）承接這個因果推論；beforehand（事先）、likewise（同樣地）、instead（取而代之）都不合。
你背 therefore 的時候，看到的例句大概都是放句首：Therefore, ...。所以當它出現在 is 和 tricked 中間，你反而會覺得這個位置不可能放 therefore 而不敢選。這一格的難處在位置，不在意思，答對率 41%，是這篇最低的一格。
先確認詞性：therefore 是副詞。therefore、however、as a result 這一類詞歸在「連接副詞」（linking adjunct）底下，可以出現在副詞能出現的任何位置（劍橋 English Grammar Today）；連接詞就不行，連接詞只能放在子句開頭。既然是副詞，它就適用副詞放句中的規則：be 動詞後面、助動詞後面、一般動詞前面。這句是被動語態 is tricked，therefore 插在 is 和 tricked 中間，完全合乎規則。你早就用過同樣的位置：I am never late.（我從不遲到），never 也是放在 be 動詞後面。再看語意，前一句說 The size of the food ... is magnified while that of their hand remains normal（食物的尺寸被放大，手的尺寸維持正常），這一句說大腦被騙以為吃得比實際多，前因後果，要填的就是「因此」。
beforehand（事先、預先）是時間副詞，這裡沒有「在某事之前」的時間對照。likewise（同樣地）用於兩件性質相同、地位平行的事，但前後兩句是因與果，不是並列。instead（取而代之、反而）表示「不是 A 而是 B」的替換或轉折，前後句沒有被替換掉的東西。轉承語是克漏字每年必考的一塊：109 年第 28 格考 And yet（然而），判斷方式是「能不能單獨加逗號放句首」；這一格反過來考「能不能放句中」，兩題合起來看，你就掌握了轉承語的兩個檢查角度。
therefore（因此）、thus（因此、於是）、consequently（因此、結果）、as a result（結果、因此）、trick sb into Ving（騙某人去做……）、fool sb into Ving（哄騙某人做……）、beforehand（事先）、likewise（同樣地）、instead（取而代之、反而）、instead of（而不是……）。
Researchers from a university in Japan have developed "diet-glasses" that play tricks with one's perception of food, which could be helpful to people on a diet.
A camera and a viewing system are built 26 these glasses. As the wearer brings the food toward their mouth, the camera captures an image of the food. It replays the image back through the glasses after processing it on an attached computer. The size of the food they are about to eat is magnified while 27 of their hand remains normal. Their brain is 28 tricked into thinking they are eating more than they really are. The study showed that participants who wore the glasses ate 9.3 less than those who did not wear them.
The team has also developed a special device which uses scent bottles and visual trickery to make the wearers of these glasses think that the plain snack they are eating is 29 than it actually is. The device, for instance, can be set to 30 one's favorite flavor. Recent experiments with this device showed that 80 of the participants were fooled by the smell. For example, some participants thought that they were eating a chocolate snack, but in fact they were not.