春节是中华民族阖家团圆的传统节日,正像明星王宝强所唱的那样,“有钱没钱,回家过年”。从这一国情出发,国家决定不再实行春运期间火车票提价的做法。这一做法的道理是 ①价格对春运不起调节作用 ②价格对生活必需品需求量影响比较小 ③火车价格提高会刺激汽车航空运输的需求 ④价格不变有利于维护人民群众的利益 A.①② B.②④ C.①③ D.②③ Paper produced every year is ________ the world's production of vehicles. A. the three times weight of B. three times the weight of C. as three times heavy as D. three times as heavier as