Suppose this is the flight path of the ball.I retreat to a position far behind the table.The ball has just fallen.I start with the paddle well above and behind the ball. 假设这是球的飞行路线，我退到离球台很远的地方，球正好落下来，我向球的后上方引拍。
Ensuring that the projectiles do not burn up or deform from reentry friction while sustaining a precise, nearly vertical flight path would be extremely difficult. 要确保炮弹不会因进入大气的摩擦而烧毁或变形，同时还要维持近乎垂直下降的精确飞行路线，可说极为困难。
