问题
选择题
It is said that the gravity on Mars is only about __________ of the gravity on earth．
A．three-eighths
B．third-eighth
C．three-eighth
D．third-eighths
答案
答案：A
题目分析：句意：据说火星上的重力是地球上重力的八分之三。分数的表达为分子用基数词，分母用序数词，当分子大于一时，分母的序数词用复数形式；故选A。