GWD2-Q40

Two centuries ago, Tufe Peninsula became separated form the mainland, isolating on the newly formed Tufe Island a population of Turfil sunflowers. This population’s descendants grow to be, on average, 40 centimeters shorter than Turfil sunflowers found on the mainland. Tufe Island is significantly drier than Tufe Peninsula was. So the current average height of Tufe’s Turfil sunflowers is undoubtedly at least partially attributable to changes in Tufe’s environmental conditions.

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

A. There are no types of vegetation on Tufe Island that are known to benefit from dry conditions.
B. There were about as many Turfil sunflowers on Tufe Peninsula two centuries ago as there are on Tufe Island today.
C. The mainland’s environment has not changed in ways that have resulted in Turfil sunflowers on the mainland growing to be 40 centimeters taller than they did two centuries ago.
D. The soil on Tufe Island, unlike that on the mainland, lacks important nutrients that help Turfil sunflowers survive and grow tall in a dry environment.
E. The 40-centimeter height difference between the Turfil sunflowers on Tufe Island and those on the mainland is the only difference between the two populations.

答案[C]

做题时，选了C, 但仔细看，觉得这到题很怪，google 半天也没找到满意的解释。

我的理解是这样的，请大家看看对不对。
Premises: TP 脱离mainland 变成了TI岛。 TI上的花要比mainland上的花矮 40cm. 因为TI 岛比过去是TP时干燥。
Conclusion: 岛上花的变化至少部分原因是因为岛的环境因素造成的。

Assumption: [C] mainland' environment has not changed

这道题目是排除它因，选项 C 排除了Mainland environment 变化而导致花长高了40cm, 从而conclusion 成立。