In reality, these spots most often develop 17 mild to moderate trauma to your nail.
答案：(B) as a result of
【慣用語】as a result of 表示「由於……的結果」，指出斑點是輕微或中度指甲創傷所導致的結果。in spite of（儘管）、to the best of（盡…所能）、for the sake of（為了…的緣故）皆不符合因果關係的文意。
前一段一路在否認：名字聽起來嚴重、其實通常不嚴重；很多人以為是缺鈣缺鋅、其實不是。整段這個「其實不是」的框架很強，讀到 In reality 開頭的這一句，你會順著那個框架覺得這裡也在轉折，於是 in spite of（儘管）看起來特別對味。
四個選項都是幾個字合起來當一個介系詞用、後面都接名詞（劍橋 English Grammar Today 的 Prepositions 條目），可見這一格考的是空格前後兩件事的關係。前面是 these spots most often develop（這些斑點多半會長出來），後面是 mild to moderate trauma to your nail（指甲受到輕度到中度的創傷），創傷是原因、斑點是結果，要的是表結果的 as a result of。把它換成 because of 讀一次，語意完全成立，這是最快的驗算法。另外提醒一個常見的落差：develop 這個字，你的印象大概只有「發展、開發」，在醫學語境裡它是不及物的「（症狀）出現、長出來」，認出這一點才看得到原因與結果這條線。答對率四成五，鑑別度只有 28：整段的否認框架太強，讀得越進去的人越容易覺得這一格當然又是在轉折，忘了先確認這一句自己在做什麼事。
in spite of（儘管）要求前後語意相反，但輕到中度的創傷正是斑點出現的原因，不是阻力。to the best of 只出現在 to the best of my knowledge、to the best of my ability 這幾個說法裡，後面固定接 knowledge、ability、belief 這類名詞，接 trauma 根本不成句，片語本身的形態就不完整，可以一眼刷掉。for the sake of（為了…的緣故）表目的，斑點不會為了創傷而長出來。
as a result of（由於…的結果）、result in（導致）、result from（起因於）、to the best of my knowledge（就我所知）、for the sake of（為了…的緣故）、mild to moderate（輕度到中度的）
Many people at some point in life have white spots on their fingernails. One of the most common causes for these little white spots is a condition called leukonychia. Although the name sounds pretty serious, the condition typically 16 . And while many people think the white spots are caused by a calcium or zinc deficiency, that's generally not the case.
In reality, these spots most often develop 17 mild to moderate trauma to your nail. If you can't think of anything that would have injured your nail, consider the fact that nails grow very slowly, so the injury 18 weeks before the spots ever appeared. The spots could also be a sign of a mild infection or allergy, or a side effect of certain medications.
19 the source of the injury, these spots typically do not require any treatment and should go away as your nail grows out. And they should not return unless you suffer another injury to a nail. However, this generally 20 when only a single or a few nails are affected. If all of your nails are showing white spots, the leukonychia could be related to another more serious condition such as anemia, cardiac disease, diabetes, or kidney disease.