[误] Three-fourths of the apples was ruined.

[正] Three-fourths of the apples were ruined.

注：英语以分数为主语时，由其后接的名词决定动词的单复数，例句中的 apples 为复数，故动词应改为复数的 were。但 Three-fourths of the crop was ruined.(四分之三的收成都毁了。)