GMAT/留學申請專業顧問 Donz 之資訊交流園地

在許多情形下，是無法判斷是否有跳躍思考，或是因果不可導置的情況。這時可以簡單瞭解一下 Argument 的因果關係，如果是看到結果找原因的 Argument，答案選項常常出現否定其他原因的答案選項。

原因應該不難懂，畢竟作者認定這個原因造成已知的結果，當然是不允許其他原因的出現。

For example:

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The milk of many mammals contains cannabinoids, substances that are known to stimulate certain receptors in the brain. To investigate the function of cannabinoids, researchers injected newborn mice with a chemical that is known to block cannabinoids from reaching their receptors in the brain. The injected mice showed far less interest in feeding than normal newborn mice do. Therefore, cannabinoids probably function to stimulate the appetite.

Which of the following is an assumption on which the argument depends?

Ans: The chemical that blocks cannabinoids from stimulating their brain receptors does not independently inhibit the appetite.

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此題目是說，注射阻擋 cannabinoids 的化學物質會導致老鼠沒有食慾，所以作者認為 cannabinoids 會造成老鼠沒有食慾。

而此項實驗結果已經是固定或是已知，所以作者的結論是在推原因，所以答案選項指出此化學物質，不會造成阻礙食慾。特別強調 independently，

是指出此化學物質，不會獨自成為食慾不振因素。如果沒有這 Assumption，那 chemical 變成食慾不振的元兇，因此就成為了 weaken cannabinoids 和食慾不振的關連。

所以此 Assumption 答案選項，排除了他因的可能性。