2.race的意思：to compete against someone or something in a race，所以compete的意思要比race廣，math是不是打錯了，如果是match的話，if you are matched against someone else in a game or competition, you are competing against them 所以compete=be matched against
3.fear是動詞或名字，而affraid是形容詞，所以不用進行區分
如果要真正分清很多看似近義的詞之間的區別，只有壹個辦法，用原版的完全英英對照的詞典，這樣意思和用法上的區別就壹目了然了