In our class of the students boys.A. third fifths; isB. third fifth; areC. three fifth; i

问题补充：

In our class of the students boys.

A. third fifths; is

B. third fifth; are

C. three fifth; is

D. three fifths; are

答案：

A. third fifths; is

B. third fifth; are

C. three fifth; is

(答案→)D. three fifths; are

解析：分数在英语中通常是借助于基数词和序数词来共同表达的。其中基数词表示分子，序数词表示分母。分子超过1，分母要加s.分数修饰名词时，若该名词是不可数名词只能用单数；若是可数名词，用单数或复数均可。但是，若它们在句子中作主语，则谓语动词是用单数还是复数取决于名词，即与分数所修饰的名词保持一致。