题目：
--- How many students are there in your class? --- Forty，and ________ of us are girls.
A．three fifths
B．three fifth
C．third five
D．third fifths
答案：
答案：A
题目分析：句意：你们班上有多少学生？40个，五分之三是女生。分数的表达，分子用基数词，分母用序数词，如one third1/3；当分子大于一时，分母要用复数形式，如two thirds；结合题意故选A。
