题干
已知三棱柱有5个面、6个顶点、9条棱，四棱柱有6个面、8个顶点、12条棱，五棱柱有7个面、10个顶点、15条棱，…，由此可以推测n棱柱有____个面，____个顶点，____条棱．
答案(点此获取答案解析）
n+2,2n,3n
pening and reform policy, people in China are ______ than they were thirty years ago.
