飞艇前五后五定位方法

简介：The old man Yan who teaches Chinese class took time off to take care of his old wife at home because she was sick. The students in Class 1 of Grade 3 cheered collectively, thinking that they could escape the boring Chinese class, but they did not expect that the math teacher was holding a pile of ink-scented books. Mathematics papers fell from the sky, and with a smile, she announced that all four classes in the morning would be hers.