题目

I grew up in a house where the TV was seldom turned on and with one wall in my bedroom entirely lined with bookshelves, most of my childhood was spent on books I could get hold of. In fact, I grew up thinking of reading as natural as breathing and books unbelievably powerful in shaping perspectives （观点）by creating worlds we could step into, take part. in. and live in. With this unshakable belief, I, at. fourteen, decided to become a writer. Here too, reading became useful. Every writer starts off knowing that he has something to say, but being unable to find the right ways to say it. H物体自楼顶处自由落下(不计空气阻力), 落到地面的速度为v． 在此过程中, 物体从楼顶落到楼高一半处所经历的时间为：    (      ) A． v/2          B． v/(2g)        C．         D．