像aneight-year-oldgirl之类要加old,那aneighthundred-wordarticle为什么不用加long呢
说成aneighthundred-word-longarticle可不可以呢,还有atwo-weekvacation可不可以说atwo-week-longvacation和twoweeks‘vacation说法有什么区别是不是只能说twoweeks’time