If these trousers are too short ,buy a longer ____.

题目

If these trousers are too short ,buy a longer ____.
答案是pair,为什么不用one?
Mary broke a ___ while she was washing up.
答案是glass for wine ,为什么不用glass of wine

答案

1.Trouser的意思是特指裤子的裤管部分,一条裤子要有一对裤管,所以要用pair, trouser要加s变成trousers才当裤子讲.
2.Mary是在刷杯子的时候打碎的杯子,所以她打碎的是杯子而不可能是酒,glass for wine 是说盛酒的杯子.