蜗杆传动的正确啮合条件之一是：蜗杆的螺旋线升角与蜗轮的分度圆螺旋角大小相等，方向相反。
参考答案：错
______ has Miss Green taught in your school? For about six years.
A. How long B. How soon C. How far
藏象
