绿飞板等待消失
while not disappear(): wait() 等飞板
正文
# disappear() 判断绿飞板是否消失
Flyer[i].disappear()
# 绿飞板会自己消失，先等它消失再走
while not Flyer[i].disappear():
wait()
# 第51、53、56 题靠 disappear 等飞板
Flyer[i].step(1)
# 多块飞板要逐块等：配合 for 循环
for i in range(3):
while not Flyer[i].disappear():
wait()
# 若写 while Flyer[i].disappear() 会反
Dev.step(1)