意思一样,但是后面那个好像有点不够规范前面那个two-month 做 vacation的定语后面那个months' vacation是一个整体,一般来说two months' 之前是没有a的这两种结构做主语的时候,主语是不一样的例:a two-month vacation is enough (主语是vacation)
two months' vacation is enough (主语是two months' vacation)变成四个月
two two-month vacations are enough (有点奇怪,但是是正确的)
four months' vacation is enough