All the classmates took the difficult exam,but only _____of them _英语解答

All the classmates took the difficult exam,but only _____of them passed.(fifth)
fifths可以吗?

人气：481 ℃　时间：2020-08-23 17:49:57

解答

此处的fifth 相当于one fifth of 意思是五分之一,所以不能换成fifths ,当分子大于1时,fifth 用作fifths