一个window窗体 点击开始的话 从窗体上会落下字母到下面，然后有个计时器20秒，每一个字母都随即的落下 一个落玩再落下一个，当你在下落的期间按键盘上的字母和窗体里的一样的话，那么窗体里的那个字母将会消失，然后在落下一个。20秒过后，计算你输入正确的字数-



A window form click start　the form will fall down the letter to the following, and then have a timer for 20 seconds, every letter are immediately fall under a fall play and then drop a, when you during the whereabouts of according to the form and letters on the keyboard in the same, then window in the letter will be disappeared, and then in the fall under a. 20 seconds later, calculate you enter the correct number of words