Our class is made up of 54 students are girls.A. of which two-fifthsB. of whom two-fifth

问题补充：

Our class is made up of 54 students, are girls.

A. of which two-fifths

B. of whom two-fifths

C. two-fifth of which

D. two-fifth of whom

答案：

A. of which two-fifths

(答案→)B. of whom two-fifths

C. two-fifth of which

D. two-fifth of whom

解析：定语从句。五分之二 two-fifths 排除C,D

先行词为students 所以选B