Each of the six science Olympiads 22 its specific aims.
答案：(A) has
Each of + 複數名詞，主詞中心語是單數的 each，動詞須用單數 has；不受介系詞片語裡的複數 Olympiads 影響。have／are 用於複數主詞，is 語意不合（此處需要「擁有」的動詞而非 be 動詞）。
空格前面緊貼著 Olympiads（複數），耳朵一順就填了 have。這正是本題設下的陷阱：真正的主詞不是離空格最近的那個字。
先把主詞的中心語找出來。Each of the six science Olympiads 裡，主詞的中心語是 Each（每一個），of the six science Olympiads 只是介系詞片語，用來說明「從哪一群裡面挑出每一個」。Each 一次只看一個，所以是單數，動詞用第三人稱單數 has。國中學過的 One of my friends is a doctor. 是同一個道理：主詞是 One，不是 friends。再看語意：後面接 its specific aims（它自己的具體目標），要的是「擁有」，be 動詞塞不進去。鑑別度高達 61，這一題分開的正是兩種讀法：跟著最近的名詞走的人填複數，先找到中心語 Each 的人填單數。介系詞片語隔在主詞與動詞中間，是主詞與動詞一致最常見的考法。
have：複數動詞，只有在主詞是 the six science Olympiads 時才對，但那是介系詞 of 的受詞。is：數對了，語意不對——這一句要說的是每一個奧林匹亞「有」自己的目標，不是「是」自己的目標。are：數與語意兩層都錯。
each of ＋ 複數名詞 ＋ 單數動詞（其中的每一個……）、one of ＋ 複數名詞 ＋ 單數動詞（……當中的一個）、specific aims（具體的目標）、be three-fold（分成三方面）、most important of all（最重要的是）、all over the world（全世界）。
There are six international science Olympiads in the world. They are all organized with a simple intention—to 21 global understanding and mutual appreciation among young scientists in all countries. Each of the six science Olympiads 22 its specific aims.
The aims of the International Mathematical Olympiad (IMO), for example, are three-fold. With arduous but interesting math problems, the first aim of the IMO is to discover, to encourage and, most important of all, to challenge 23 gifted young people all over the world. Secondly, it is by participating in any IMO contest that young mathematicians of all countries can foster friendly 24.
Based upon its second aim, more international exchanges are encouraged and established. Any IMO contest brings not only young mathematicians together but also their instructors; 25, the IMO has its final aim to create opportunities for the exchange of information on math schedules and practice throughout the world.