Piaget 30 to establish a body of psychology all his life and became a very influential figure in educational psychology.
答案：(C) sought
seek to V 意為「設法、致力於做某事」，sought 是 seek 的過去式：皮亞傑終其一生致力於建立一套心理學體系；forgot（忘記）、afforded（負擔得起）、tended（傾向於）語意都不合。
看到空格後面接 to establish，你會直覺去找「習慣接 to V」的那個字。但這一題用句型篩不出答案：forget to V、afford to V、seek to V、tend to V 四個全都成立，結構這一關四個選項一起過，只能靠語意分。
先看骨幹。主詞是 Piaget，空格就是主要動詞，all his life（終其一生）是時間副詞，後半句由 and 接上第二個動詞 became。所以這一格的動詞，語氣要撐得起「終其一生」與「成為極具影響力的人物」兩個條件。seek 是「尋求、追求」，接不定詞時 seek to V 表示「設法、致力於」，語氣積極而持續，兩個條件都對得上。驗算法：把 all his life 拿掉唸一遍，再放回去唸一遍，語氣撐不住 all his life 的選項就不是答案。還有一關在認字。seek 的三態是 seek-sought-sought，與國中學過的 buy-bought-bought、bring-brought-brought、think-thought-thought、fight-fought-fought 同屬 -ought 這一組。要先認得出 sought 是 seek，才輪得到辨義。
forget to V 是「忘記要做某事」，forget V-ing 才是「忘記做過」，這一組國中學過；放進來會變成「終其一生忘記要建立心理學體系」，語意不通。afford to V 是「負擔得起」，配的是花錢或花時間的事，而且多半用在否定與疑問（can't afford to），肯定直述句少見。tend to V 是「傾向於」，講的是性向不是作為。這一格與後半的 became 由 and 連起來，是同一個人先後做的兩件事，前面得是實際投入才接得出「於是成為影響深遠的人物」；一種傾向接不出這個結果。
seek to V（設法、致力於）、seek help／advice（尋求協助／建議）、much sought-after（炙手可熱的）、tend to V（傾向於）、afford to V（負擔得起）、forget to V（忘記要做）／forget V-ing（忘記做過）。
Jean Piaget, a psychologist and pioneer in the study of child intelligence, was born in Switzerland in 1896. At age 10, he managed his first 26, a description of a partly albino sparrow he observed in a public park. At age 15, he 27 to devote his life to developing a biological explanation of knowledge.
He began his career as a zoologist, 28 mollusks and their adaptations to their environment. 29 age 21, he had already published 25 professional papers on that topic.
Later, after working with Alfred Binet in Paris, he became interested in levels of logic used by children taking standardized tests on intelligence. Piaget 30 to establish a body of psychology all his life and became a very influential figure in educational psychology. His works were all written originally in French and were later translated into English.