The round windows are indeed pleasant to the eye, but they actually were designed for reasons 16 aesthetics.
答案：(D) other than
other than 是「除…之外的其他、不同於」，本句指圓窗其實是基於美觀以外的理由而設計；except for 用於「整體中扣除例外」，contrary to（與…相反）語氣過強，more of（更像是）句構不合。
答對率 21%。
看到「除了…以外」這幾個中文字，你腦中第一個跳出來的是 except for，於是掉進陷阱。這兩個片語的中文翻譯很接近，用法卻不同。
other than 的重點在「不同於、除此之外的另一類」，強調的是另有其他；except for 的重點在「整體中扣掉某個例外」，前面通常有 all、everything、everyone 這類表示全體的字——劍橋文法的例句 I like all fruit except (for) oranges.（我喜歡所有水果，柳橙除外）就是典型。本句說的是「圓窗其實是基於美觀以外的理由而設計」，後面接的是另一類理由（結構安全），不是從整體裡扣掉誰，所以要用 other than。
句子前半 The round windows are indeed pleasant to the eye 先承認「確實好看」，接著 but…actually 一轉，就是要說「真正的原因不是美觀」。indeed…but actually 這組讓步轉折是本題的方向指標；下一句 In the early days of aviation, plane windows were square in shape 也預告了真正的原因與飛安有關。
contrary to 是「與…相反」，語氣太強——設計理由並非「與美觀相反」，只是「不只是美觀」；more of 是「更像是」，後面要接名詞當補語，句構不合。
other than（除…之外的其他）、none other than（正是、不是別人正是）、except for（除了…之外）、apart from（除…之外）、contrary to popular belief（與一般認知相反）。
Airline passengers may have noticed that all plane windows have rounded edges, instead of the hard corners commonly found in our house. The round windows are indeed pleasant to the eye, but they actually were designed for reasons 16 aesthetics.
In the early days of aviation, plane windows 17 square in shape. Then as commercial air travel became popular in the 1950s and airplanes began flying higher and faster, three planes mysteriously broke apart in midair. The cause? Square windows. Scientists found that sharp corners are natural weak spots where stress concentrates. The problem is 18 when airplanes fly at higher altitudes, where the difference between the inside and outside pressure increases, causing added stress. When subjected to repeated pressurization high in the sky, the four corners on a square window may 19 .
Curved windows, on the other hand, distribute stress around more evenly, reducing the likelihood of cracks or breaks. Circular shapes are also stronger and resist deformation, and therefore can 20 extreme differences in pressure inside and outside of an aircraft. Thus, round windows are a major safety innovation that keeps planes from disintegrating mid-flight. They are also used on ships and spacecraft for their greater structural integrity.