The girl looked at me with a _______expression. Maybe the problem was quite ______. A. puzzled; puzzling B. puzzling; puzzled C. puzzled; puzzled D. puzzling; puzzling 答案:A2003年11月25日,沱江龙西大桥(俗称沱三桥)工程开工仪式在城北新区举行,垅西大桥全长410.50米,对近似数410.50,下列说法正确的是( )A.精确到百位,有3个有效数字B.精确到百位,有5个有效数字C.精确到百分位,有3个有效数字D.精确到百分位,有5个有效数字