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.
答案：(C) therefore
分號後延續前句邏輯：正因為比賽把數學家和指導老師聚在一起，「因此」IMO 的終極目標就是促成資訊交流，therefore 表順接因果。whereas（然而，對比）、nevertheless（然而，轉折）、likewise（同樣地）都不符合這裡的順接因果語氣。
分號前面是 not only ... but also ...，很容易讀成「這一句在並列兩件事」，於是找一個表示補充或對比的轉承語。答對率四成二，鑑別度只有 19，是全卷最分不出高低的一題。原因就在這裡：not only ... but also 的框架越熟，越容易把注意力鎖在分號前面那兩個並列的名詞上，沒有回頭問分號後面那一句在做什麼——連高分群考生也大量失手。
分號不是句界，前後兩半在同一句裡，關係自己就看得出來。前半：任何一場 IMO 競賽把年輕數學家與他們的指導老師聚在一起。後半：IMO 的最終目標是為全世界數學課程與教學經驗的交流創造機會。人先聚在一起是條件，交流的機會是結果，中間是順接的因果，用 therefore（因此）。這是邏輯勾環：轉承語本身就是線索，先確定前後兩半是哪一種關係，再挑詞。
whereas（然而）：把兩件相反的事並排比較，但前後兩半同向。nevertheless（儘管如此）：要有讓步關係，前半必須是一個會讓後半難以成立的事實，這裡沒有。likewise（同樣地）：後面要接一件與前面平行的事，而後半不是再舉一件同類的事，是前面那件事帶出來的結果。
not only ... but also ...（不只……而且……）、bring people together（把人聚在一起）、create opportunities for（為……創造機會）、the exchange of information（資訊交流）、throughout the world（在全世界）、whereas（然而，用於前後對比）。
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.