Despite their great 28 , however, most domesticated apples can be traced back to a common ancestor, the wild apple of Central Asia, Malus sieversii.
答案：(A) variety
語意「儘管品種『多樣』，大多數家化蘋果卻可以追溯到共同祖先」，variety（多樣性）呼應前文提到的7000種蘋果；harvest（收成）、condition（狀況）、discovery（發現）都不合。
variety 你最熟的是片語 a variety of（各式各樣的），習慣把它當成一個整體記，反而對 variety 單獨當名詞時的意思沒把握。這裡前面是 their great，指的是「它們龐大的多樣性」。順帶把另一個常考義一起收進來：variety 也可以指「品種」，且是可數的，例 a new variety of rice（一個水稻新品種）—— 這一義跟本文的 7,000 different kinds 正好呼應。
Despite（儘管）表讓步，讓步句的兩邊必須「表面上互相矛盾」，所以只要看清楚後半句在說什麼，前面該填什麼就被鎖死了。後半句是 most domesticated apples can be traced back to a common ancestor（大多數人工栽培的蘋果都能追溯到同一個祖先），講的是「同一個源頭」。能跟「同源」形成反差的，只有「種類很多」。一多一少的張力，就是答案。再往回讀一句更確定：over 7,000 different kinds in existence（現存超過七千個品種）—— 空格是在把上一句的細節用一個抽象名詞收攏起來。這種「上一句舉細節、下一句用抽象名詞概括」的手法是學測克漏字的常客，看到 their、this、such 這類指示詞，就要往回找它到底指什麼。
harvest（收成、收穫量）—— 這一句沒有在談產量；產量的數字要到全文最後一句才出現，而且那是在講今日的產業規模，不是這裡讓步的對象。condition（狀況、條件）—— their great condition 是「狀況良好」，跟「同源」構不成矛盾。discovery（發現）—— 文中沒有提到任何發現的過程。
variety（多樣性；品種）、a variety of（各式各樣的）、a wide variety of（種類繁多的）、despite + 名詞（儘管……）、be traced back to（追溯到）、a common ancestor（共同祖先）、domesticated（馴化的、人工栽培的）。
Nutritional products that can be collected from trees include fruits, nuts, seeds, leaves, and bark. Tree products have been an important part of diets for thousands of years, from early humans 26 fruits and nuts to the first cultivation of important trees, such as mango and apple.
The apple is one of the world's most cultivated fruit trees, 27 over 7,000 different kinds in existence. Despite their great 28 , however, most domesticated apples can be traced back to a common ancestor, the wild apple of Central Asia, Malus sieversii. Apples have been grown for thousands of years in Asia and Europe, and 29 to North America by European colonists in the 17th century.
Today, apples are 30 eaten the world over and form the basis for multi-million dollar industries. In 2005, at least 55 million tons of apples were grown worldwide, which generated a value of about $10 billion.