One day, an idea 17 Art Fry.
答案：(B) occurred to
occur to sb 意為「（想法）浮現在某人腦中」，主詞是想法、受詞是人：有一天 Art Fry 想到一個點子；come up with 的主詞必須是人，主客顛倒，threw at（朝…扔）與 looked down upon（瞧不起）語意也不合。
要說「想到一個點子」，你第一個想到的大概是 come up with；occur 則多半只記得「發生」（The accident occurred at midnight. 意外發生在半夜）。occur 後面接 to 再接人時，意思是「（想法）浮現在某人腦中」，即中文的「某人忽然想到」。
四個選項均為動詞片語，填入後文法上都能成立，因此判斷的依據在主詞與受詞的方向。本句主詞是 an idea、受詞是 Art Fry，需要一個以想法為主詞、以人為受詞的動詞片語；劍橋詞典對 occur to sb 的釋義是「（想法）進入某人腦中」，方向與本句相符。作答線索在前文 He was bothered by a small irritation every Sunday as he sang in the church choir.（他每個星期天在教堂唱詩班唱歌時，都被一件小事困擾），說明他長期為紙片掉落所苦，此處寫的正是他忽然想到的解決辦法。凡是四個選項均為動詞片語、文法上都填得下的題目，判斷步驟相同：先確認主詞與受詞各是動作的發出者或承受者，再檢查各選項要求的方向是否與句子一致。
came up with 的語意雖然相符，方向卻相反：come up with 的主詞須是人，如 Art Fry came up with an idea.（福萊想出一個點子）；本句主詞是 an idea，故不能選。threw at 是「朝…扔」，looked down upon 是「瞧不起」，語意與上下文不合。
an idea occurs to sb（某人想到一個點子）、It occurs to sb that…（某人忽然想到…）、a thought strikes sb（某人腦中閃過一個念頭）、come up with an idea（想出點子）。
Art Fry was a researcher in the 3M Company. He was bothered by a small irritation every Sunday as he sang in the church choir. That is, after he 16 his pages in the hymn book with small bits of paper, the small pieces would invariably fall out all over the floor.
One day, an idea 17 Art Fry. He remembered a kind of glue developed by a colleague that everyone thought 18 a failure because it did not stick very well. He then coated the glue on a paper sample and found that it was not only a good bookmark, but it was great for writing notes. It would stay in place 19 you wanted it to. Then you could remove it 20 damage.
The resulting product was called the Post-it, one of 3M's most successful office products.