听写。（请将听到的成语用楷书或行书在田字格里规范、工整地书写出来。）
名正言顺 萍水相逢 销声匿迹
Is it Fanny's marker?[ ]
A. No! It's his marker.
B. Yes! It's not her marker.
C. Yes! It's her marker.
叙述空腹式悬链线无铰拱拱轴系数的确定方法。
