空间定向障碍法确定角度、高度、速度的情况尤为严重,因為人的方向感主要取決於人的視覺。 Wolverton, Mark. The Father Of Blind Flying. Invention and Technology (American Heritage Institute). Fall 2008, 23
比利·乔尔Island, in the Levittown section of Hicksville. We had a Levitt house, Cape Code, on the quarter acre. ... My father was a classically trained pianist