—They have built another new library for the students—About of the books in their library

问题补充：

—They have built another new library for the students

—About of the books in their library are written in English．

A. four fifth

B. four fifths

C. fourth fifths

D. fourths fifth

答案：

A. four fifth

(答案→)B. four fifths

C. fourth fifths

D. fourths fifth

解析： 英语分数，分子读做基数词，分母读做序数词。如果分子是一，则分母直接读做序数词；如果分母大于一，则序数词要加s变成复数。

如:2/3 读做 two thirds.故选B,五分之四。