请简述正手发奔球技术练习中常见的问题。Please briefly describe common mistakes that may happen in the practice of forehand rush serve. 评分规则: 手腕过紧这会导致击球力量小，球速慢。练习时，应注意引拍动作要放松；引拍幅度不够，这同样会使击球力量较小，球速慢，练习时，应注意稍加大引拍幅度。挥拍方向过于向前下方，这会导致球的飞行弧线过高，球速变慢。因此，练习时，应注意与平击发球向后上方引拍和向前下方挥拍不同，发奔球时应向后方引拍、向前稍下的方向挥拍击球。A tight wrist will result in less power and a slower ball. When practicing, should pay attention to lead the racket action to relax; The beating range is not enough, which will also make the hitting power is small, the ball speed is slow, practice, should pay attention to slightly increase the beating range. Swing too far forward and down, which causes the ball to curve too high and slow down. Therefore, when practicing, you should pay attention to the difference between driving the racket back and up and driving the racket forward and down, and driving the racket back and slightly down the direction of driving the racket forward. 3 乒乓球反手推-拨技术 单元测验